drm/amd/display: add mod_freesync_user_enable to dm_connector_state

We don't currently expose variable refresh rate, but add the state to the
connector state to make it easier to maintain the support for it from a
hw support perspective while we figure out the uapi for drm.
Reviewed-by: NHarry Wentland <harry.wentland@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

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

@@ -1686,6 +1686,7 @@ struct dm_connector_state {
 	uint8_t underscan_vborder;
 	uint8_t underscan_hborder;
 	bool underscan_enable;
+	struct mod_freesync_user_enable user_enable;
 };
 
 #define to_dm_connector_state(x)\