For each CRTC state, check the size of Gamma and Degamma LUTs  so
unexpected and larger sizes wouldn't slip through.

TEST: IGT:kms_color::pipe-invalid-gamma-lut-sizes

v2: fix assignments in if clauses, Mark's email.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Mark Yacoub <markyacoub@chromium.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>