Input: Add flags to RawDeviceEvent

Add a flags member which will be copied wholesale into the resultant
xXIRawEvent.

Signed-off-by: Daniel Stone <daniel@fooishbar.org>

include/eventstr.h

@@ -204,6 +204,7 @@ struct _RawDeviceEvent
         int32_t  data_raw[MAX_VALUATORS];     /**< Valuator data as posted */
         int32_t  data_raw_frac[MAX_VALUATORS];/**< Fractional part for data_raw */
     } valuators;
+    uint32_t flags;       /**< Flags to be copied into the generated event */
 };
 
 #ifdef XQUARTZ