headers_check fix: linux/if_tr.h

fix the following 'make headers_check' warning:

  usr/include/linux/if_tr.h:37: found __[us]{8,16,32,64} type without #include <linux/types.h>

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
diff --git a/include/linux/if_tr.h b/include/linux/if_tr.h
index 5bcec8b..fc23aeb 100644
--- a/include/linux/if_tr.h
+++ b/include/linux/if_tr.h
@@ -19,6 +19,7 @@
 #ifndef _LINUX_IF_TR_H
 #define _LINUX_IF_TR_H
 
+#include <linux/types.h>
 #include <asm/byteorder.h>	/* For __be16 */
 
 /* IEEE 802.5 Token-Ring magic constants.  The frame sizes omit the preamble