linux: UAPI for L2-NHG and MAC-ECMP

linux headers needed for MH MAC-ECMP support

Signed-off-by: Anuradha Karuppiah <anuradhak@cumulusnetworks.com>

include/linux/neighbour.h

@@ -29,6 +29,7 @@ enum {
 	NDA_LINK_NETNSID,
 	NDA_SRC_VNI,
 	NDA_PROTOCOL,  /* Originator of entry */
+	NDA_NH_ID,
 	__NDA_MAX
 };
 

include/linux/nexthop.h

@@ -50,6 +50,7 @@ enum {
 	 */
 	NHA_GROUPS,	/* flag; only return nexthop groups in dump */
 	NHA_MASTER,	/* u32;  only return nexthops with given master dev */
+	NHA_FDB,	/* nexthop belongs to a bridge fdb */
 
 	__NHA_MAX,
 };