drm/amd/display: Revert "Fallback to SW cursor if SubVP + cursor too big"

This reverts commit a4f1b042 since
returning false in case of SubVP results in no cursor being visible on
desktop as there is no sw cursor fallback path on all platforms.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Alvin Lee <Alvin.Lee2@amd.com>
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>