drm: apple: Support sync objects

Both mutter[0] and KWin[1] are using the KMS drm device for explicit
sync in their screen casting implementation. This fails in both cases
since the KMS device does not provide DRM_CAP_SYNCOBJ_TIMELINE.
Support for this is implemented in generic DRM so setting the two
necessary feature flags.

0: https://gitlab.gnome.org/GNOME/mutter/-/issues/4224
1: https://invent.kde.org/plasma/kwin/-/merge_requests/7941

Signed-off-by: Janne Grunau <j@jannau.net>

Author: jannau

drivers/gpu/drm/apple/apple_drv.c

@@ -73,7 +73,7 @@ static const struct drm_driver apple_drm_driver = {
 	.desc			= DRIVER_DESC,
 	.major			= 1,
 	.minor			= 0,
-	.driver_features	= DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
+	.driver_features	= DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC | DRIVER_SYNCOBJ | DRIVER_SYNCOBJ_TIMELINE,
 	.fops			= &apple_fops,
 };