- Copy stable/10@296371 to releng/10.3 in preparation for 10.3-RC1
builds.
- Update newvers.sh to reflect RC1.
- Update __FreeBSD_version to reflect 10.3.
- Update default pkg(8) configuration to use the quarterly branch.

Approved by: re (implicit)

MFC r274670, r274671, r276168:

Moves all the duplicate code to a single function.

Verify for invalid modes and unwanted flags before pass the new flags to
driver.

Make gpio_default_map_gpios() static. No functional changes.

Improves the GPIO API description a little bit.

gpio_pin_max must return the maximum supported pin number and not the total
number of pins on the system.

MFC r273799:

Make the GPIO children attach to the first unit available and not only to
unit 0.

This fix a bug where a GPIO controller could fail to attach its children
(gpioc and gpiobus) if another GPIO driver attach first.

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix undefined behaviour in several gpio_pin_setflags() routines (under
sys/arm and sys/mips), squelching the clang 3.3 warnings about this.

Noticed by: tinderbox and many irate spectators
Submitted by: Luiz Otavio O Souza <loos.br@gmail.com>
PR: kern/177759
MFC after: 3 days

The GPIO drivers were initialising their mutexes with type of
MTX_NETWORK_LOCK. This is wrong since these mutexes have nothing to do
with networking.

Import the initial CPU support for the MIPS RALink RT305x SoC.
This is a MIPS4KC CPU with various embedded peripherals, including
wireless and ethernet support.

This commit includes the platform, UART, ethernet MAC and GPIO support.
The interrupt-driven GPIO code is disabled for now pending GPIO changes
from the submitter.

Submitted by: Aleksandr Rybalko <ray@dlink.ua>