drm/amd/display: fix YUV video color corruption in DCN401

drm/amd/display: fix YUV video color corruption in DCN401

[Why]
Missing check causes sequence error which results in chroma
 filter coefficients not being updated in certain modes
 when we display YUV video in fullscreen.  This results in
 color corruption in video

[How]
Add back chroma_coef_mode check in dscl_set_scl_filter
 so that filter coefficients are calculated and updated when
 we have YUV surface

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Acked-by: Zaeem Mohamed <zaeem.mohamed@amd.com>
Signed-off-by: Samson Tam <samson.tam@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>