drm/amd/display: We shouldn't set format_default on plane as atomic driver

This is still a leftover from early atomic brinup days.

Signed-off-by: Harry Wentland <harry.wentland@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>
Cc: stable@vger.kernel.org

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -3134,8 +3134,6 @@ static int amdgpu_dm_plane_init(struct amdgpu_display_manager *dm,
 
 	switch (aplane->base.type) {
 	case DRM_PLANE_TYPE_PRIMARY:
-		aplane->base.format_default = true;
-
 		res = drm_universal_plane_init(
 				dm->adev->ddev,
 				&aplane->base,