headers_check fix: linux/hiddev.h

fix the following 'make headers_check' warning:

  usr/include/linux/hiddev.h:40: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

include/linux/hiddev.h

@@ -27,6 +27,8 @@
  * Vojtech Pavlik, Ucitelska 1576, Prague 8, 182 00 Czech Republic
  */
 
+#include <linux/types.h>
+
 /*
  * The event structure itself
  */