drm/amd/display: Move hdr_metadata from plane to stream

Need to move HDR Metadata from Surface to Stream since there is only one
infoframe possible per stream.

Also cleaning up some duplicate definitions.

Signed-off-by: Anthony Koo <anthony.koo@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>