uapi: move IPPROTO_L2TP to in.h

IPPROTO_L2TP is currently defined in l2tp.h, but most of
ip protocols are defined in in.h file. Move it there in order
to keep code clean.
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

include/uapi/linux/in.h

@@ -68,6 +68,8 @@ enum {
 #define IPPROTO_PIM		IPPROTO_PIM
   IPPROTO_COMP = 108,		/* Compression Header Protocol		*/
 #define IPPROTO_COMP		IPPROTO_COMP
+  IPPROTO_L2TP = 115,		/* Layer 2 Tunnelling Protocol		*/
+#define IPPROTO_L2TP		IPPROTO_L2TP
   IPPROTO_SCTP = 132,		/* Stream Control Transport Protocol	*/
 #define IPPROTO_SCTP		IPPROTO_SCTP
   IPPROTO_UDPLITE = 136,	/* UDP-Lite (RFC 3828)			*/

include/uapi/linux/l2tp.h

@@ -13,8 +13,6 @@
 #include <linux/in.h>
 #include <linux/in6.h>
 
-#define IPPROTO_L2TP		115
-
 /**
  * struct sockaddr_l2tpip - the sockaddr structure for L2TP-over-IP sockets
  * @l2tp_family:  address family number AF_L2TPIP.