headers_check fix: linux/ipv6_route.h

fix the following 'make headers_check' warning:

  usr/include/linux/ipv6_route.h:42: found __[us]{8,16,32,64} type without #include <linux/types.h>
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>

include/linux/ipv6_route.h

@@ -13,6 +13,8 @@
 #ifndef _LINUX_IPV6_ROUTE_H
 #define _LINUX_IPV6_ROUTE_H
 
+#include <linux/types.h>
+
 #define RTF_DEFAULT	0x00010000	/* default - learned via ND	*/
 #define RTF_ALLONLINK	0x00020000	/* (deprecated and will be removed)
 					   fallback, no routers on link */