[gpio] Refactor the GPIO protocol

This is a first step in a move toward using protocols to represent
individual resources. A similar change will be made to the I2C protocol
to bring it in line with how I2C is used on x86 platforms.

From the client's point of view, an instance of the ZX_PROTOCOL_GPIO
protocol now represents a single pin. The protocol remains the same,
except the "uint32_t index" has been removed from all the protocol functions.

For devices that have only one GPIO resource assigned to them, the driver
can simply call device_get_protocol() to access the GPIO protocol for the pin.
To for devices with more than one GPIO pins, a new API in the platform bus called
pdev_get_protocol() must be used instead.

In addition, we add a new protocol ZX_PROTOCOL_GPIO_IMPL, which is now
implemented by the GPIO drivers. This protocol is essentially the same as
the old GPIO protocol, except "index" has been renamed "pin".
Board drivers may use this protocol directly when doing low level system
configuration, specifying pin numbers directly.

TEST: Booted on VIM2 and Hikey.
On VIM2, USB, display, ethernet and the GPIO test driver are working properly
On Hikey, the system boots and USB is functional.

Change-Id: I44f1bc11ad9793543361a2d19d7a2de4458c334b

[dev][board] Remove some unneeded protocols from the board drivers

TEST: manual testing on vim2 and gauss
Change-Id: I884dc1bdbd1e9572bb42c40efe706b356178db64

[board][gauss] Remove support for USB dwc3 controller

At the time the origininal code was written, I didn't realize that
the A113 SOC used dwc3 for host only and used dwc2 for device mode.
We don't support dwc2, so we only run gauss in host mode.
dwc3 host support is the same as XHCI, so we can just use the
xhci driver directly and do not need the dwc3 driver at all.

Test: manual testing on gauss. USB ethernet dongle enumerates successfully.

Change-Id: I4d90e8adb5e169aba9ac10778ad2ea8c9794973e

[gauss] Gauss board driver for Amlogic RAW_NAND.

Change-Id: I0d7b657e184c43aa4b4d61bc7c1be0cb0f02dc54

[aml][pcie][dw] DW/Amlogic PCIe for Gauss

Implements a low level PCIe driver for the
Amlogic configuration of the DesignWare PCIe
controller.

The DW controller provides an address
translation unit that can be programmed to
translate addresses from the host address space
into PCI address space.

This driver configures one segment of the host's
address space to translate into the PCI ECAM
registers and programs the rest of the host's
PCI address space to be reserved for BARs.

A follow up patch will instantiate the PCI
bus driver using these address spaces.

Change-Id: I423f14ea2229af8f12b6f03882270b59acbc7a7b

[board][gauss] Switch remaining io_buffer usage to BTI aware calls

Change-Id: Ib5a8b87ef2938303e17338d8592c074fcf7f3703

[dev][board] Use io_buffer_init_physical_with_bti()

instead of the deprecated io_buffer_init_physical()
in the vim, hikey960 and gauss platform board drivers

Change-Id: Ice59d6b890c1118ce15b104d2ac673bd6119114d

[dev][aml-i2c] Remove unnecessary header file

Move the enum listing the gauss I2C ports into the gauss board driver
and stop using it in the aml-i2c driver.

Change-Id: Ic634a62fcb4108106ee3939b6c4bd72f732cdb11

[clk][amlogic][a113] Clock Protocol Driver

Implements the clock enable/disable protocol for the aml113 (meson-axg)

Change-Id: Id8d835f5fd9a384c2b8e783fb2e89088000f73b9

[amlogic][i2c] Refactor the aml-a113 I2C driver

The driver is now separately loadable and the a113 specific configuration
is now in the gauss board driver.
This will allow us to use the driver for other Amlogic platforms.

Change-Id: I821c56562016fe449bc0896e81294ebe314fd9e3

[amlogic][gpio] Refactor the aml-a113 GPIO driver

The driver is now separately loadable and the a113 specific configuration
is now in the gauss board driver.
This will allow us to use the driver for other Amlogic platforms.

Change-Id: I2e056428c359bf8016a076f73eed97591f9b415e

[soc][aml-a113] GPIO driver refactoring

Refactor the aml-a113 driver so we can use it for other Amlogic platforms

Change-Id: I25f7a703e7006200643ae917317df4014e255de1

[soc][aml-a113][i2c] I2C refactoring

Refactor aml-a113 driver so we can use it for other Amlogic platform

Step 1 of general Amlogic SOC refactoring

Change-Id: If9a02b934db72430498e7fc12246931360482225

[gauss][clocks] set and use mpll2

Change-Id: I4364dd9e7ecf5d48feb8107033a119287b643be5

[gauss] Configure USB PHY mode properly on USB connect and disconnect

Fixes hang in USB stack when unplugging a USB device

ZX-1389 #done

Change-Id: I6b3393fa8ac8829485ca74a539e6dbb31b0aece9

[dev][soc][aml-a113] Break a113_bus_t into separate structs for GPIO and I2C

Change-Id: I45f48f5065e5f21dfd9b5d7008b42ad8c32668d1

[gauss] Refactor gauss platform bus driver

Move platform bus support driver for gauss to system/dev/board/gauss.

Also move gauss i2c test driver to system/dev/board/gauss.

Amlogic A113 specific code remains in system/dev/soc/aml-a113,
which is now a static library.

Later we may move code (i2c, gpio, etc) that works for other Amlogic SOCs
may get broken out into separate libraries.

Change-Id: If2133824563be3086a8ea41064e5955d6ae4d609