[syscalls] Change vmar_... calls

- Create zx_vm_option_t type
- Change ZX_VM_FLAG_... to ZX_VM_... and make them new type.
- Change int32_t flags parameters to zx_vm_option_t options
- Make the options parameter be second.

- Modify vmar_..._old functions to keep other repos working.
Once they've all been updated these functions will go away.

ZX-2264
Test:CQ

Change-Id: I1faf4cc4e1e4dabf3d8ef680e398d83a545b0f09

[vim-display][display-test] Support NV12 layers

The single fullscreen layer can now use an NV12 image.

Test: display-test

Change-Id: Ie85f91bb4b1ecd5e476012af14fc9d872cccfc46

[display] Remove ddk calls from on_displays_changed

This change replaces get_info with per-display argument structs to
on_displays_changed, and it moves the display mode validation to a
posted task. This allow simpler locking in the impl drivers, and it
enables the addition of output parameters into the argument structs.

This change also causes ownership messages to be sent before display
changed messages. Update various clients to not rely on a particular
order of messages.

Test: Boot to virtcon/hotplug on NUC/vim/eve. Run gfxtest, gfxlatency,
and display-test

Change-Id: Id561ed7587037353c1aeeab96511481d74026bdc

[uapp] add paradise v2 support to gfxlatency

Makes this test app work on devices with older touch firmware.

Touch event parsing has also been updated to more easily
support additional devices.

Bug: none
Test: gfxlatency
Change-Id: I1c96b6bff13187eb81aba171951f9d47e172218e

[uapp] gfxlatency version 2

This makes some significant changes to this app in order to have
it be more useful for latency measurements.

The app simulates a desktop shell with 2 clients:

1. Drawing canvas that can be scrolled.
2. Cursor sprite.

The --slow-down-scale-factor flag can be used to simulate
a slower drawing canvas client. The app can be used to
determine what the minimal latency is for a gfx client and
demonstrates how you can potentially have a slow compositor
while still providing very low latency updates for some
clients under the right circumstances.

Bug: none
Test: gfxlatency

Change-Id: I30ec38d20a5f46e79418033f7ae63f095727740e

[uapp] Add vsync mode to gfxlatency test

This adds three different vsync modes to gfxlatency, ON, OFF
and ADAPTIVE.

ON, this is standard vsync behavior. Next buffer will not be
presented until new frame is ready.

OFF, single buffer mode without vsync.

ADAPTIVE, vsync is enabled but buffer is presented even if
frame is not ready in time. No tearing is noticed as long as
frames are produced in time. If a frame takes too long to
produce, then tearing might be noticed but latency is kept
short.

TEST=gfxlatency --vsync=ON

Change-Id: I786e5d9688343f2f5cc225cf4d8a723f86048387

[uapp] Add gfxlatency test

This is a small test app that can be used to determine the optimal
end-to-end latency of low-level input and graphics in zircon.

It allows accurate end-to-end latency to be measured using a high
speed camera.

TEST=gfxlatency

Change-Id: I21892a7ac76291b0a410e593d200520e17831e9e