staging: xlnxsync: Fix the uapi header license

Error: missing "WITH Linux-syscall-note" for SPDX-License-Identifier

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Vishal Sagar <vishal.sagar@xilinx.com>
Reviewed-by: Hyun Kwon <hyun.kwon@xilinx.com>
State: pending

include/uapi/linux/xlnxsync.h

@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0 */
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
 
 #ifndef __XLNXSYNC_H__
 #define __XLNXSYNC_H__