vp9: Add check to validate source input

Return invalid_params.

The check is wrapped around a new control:
VP9E_SET_VALIDATE_INPUT_HBD,
and is enabled by default.

Check is done only CONFIG_VP9_HIGHBITDEPTH build
and for bitdepth > 8.

Bug: 488585490
Change-Id: Ic79dff1bd314d4b197087d3c46d315ece8fd355c
3 files changed