media/gpu/v4l2: recognize MM21 format

MM21 is a proprietary pixel format used on Kukui devices. This CL adds
the hooks necessary for the V4L2 decoder and IP to use it.

Bug: b:123551776
Test: VDA unittest passing on Kukui

Change-Id: I3da9f7b316d31feb5c1a8b99dfc7bf4cf8adf71e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1743298
Commit-Queue: Alexandre Courbot <acourbot@chromium.org>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#685492}
3 files changed