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

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

This reverts commit 5487f1f9d25d7a480a7dfb4549552a2b52d0081a 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>