drm/amd/display: Workaround wrong HDR colorimetry with some receivers

[Why]
Some scalers do not pick up color space updates unless the DP link
is disabled/re-enabled which can result in incorrect/washed out
HDR colors in some cases.

[How]
Call set_dpms_on to disable the link, re-train and re-enable with the
updated output color space.

Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Alan Liu <HaoPing.Liu@amd.com>
Signed-off-by: Ilya Bakoulin <Ilya.Bakoulin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>