drm/amd/display: Expose more formats for overlay planes on DCN

DCN planes are universal and therefore overlay planes can use the same
formats as primary planes, unlike DCE.

Gamescope/Steam Deck would like to take advantage of this functionality
for partial composition which in some cases in our pipeline, can contain
negative values in some instances.

Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Melissa Wen <mwen@igalia.com>
Cc: Simon Ser <contact@emersion.fr>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Joshua Ashton <joshua@froggi.es>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>