drm/amd/display: Add DP YCbCr 4:2:0 support

[Why]
For supporting DP YCbCr 4:2:0 output.

[How]
Update mod_build_vsc_infopacket to support Pixel
Encoding/Colorimetry Format indication for VSC SDP rev5.

Signed-off-by: Eric Bernstein <eric.bernstein@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>