drm/amd/display: set MSA MISC1 bit 6 while sending colorimetry in VSC SDP

[Why]
It is confusing to sinks if we send VSC SDP only on some format. Today we
signal colorimetry format using MSA while in formats like sRGB.
But when we switch to BT2020 we set the bit to ignore MSA  colorimetry and
instead use the colorimetry information in the VSC SDP.

But if sink supports signaling of colorimetry via VSC SDP we should always
set the MSA MISC1 bit 6, instead of doing so selectively.

[How]
If sink supports signaling of colorimetry via VSC SDP, and we are sending
the colorimetry info via VSC SDP with packet revision 05h, then always
set MSA MISC1 bit 6.

Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>