drm/amd/display: Use pixels per container logic for DCN314 DCCG dividers

drm/amd/display: Use pixels per container logic for DCN314 DCCG dividers

[Why]
DP DSC YCbCr422 not working because dcn314_calculate_dccg_k1_k2_values
does not account for two pixels per container

[How]
Replace the contents of dcn314_calculate_dccg_k1_k2_values with the
code from the function dcn32_calculate_dccg_k1_k2_values

Reviewed-by: Charlene Liu <Charlene.Liu@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Daniel Miess <Daniel.Miess@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>