I2C: Add 16-bit read/write functions

Some audio codecs (RealTek) have 16-bit data regs. Use these
functions to access them on Ryu, etc.

TEST=Enabled RealTek 5677 codec on Ryu and was able to read
and write codec registers, reset the codec, etc.

Change-Id: I48e5adfa9d01a7662e6fe3d7f143c1bd996f538b
Signed-off-by: Tom Warren <twarren@nvidia.com>
Reviewed-on: https://chromium-review.googlesource.com/228200
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
2 files changed