bonding: add xmit_hash_policy attribute netlink support

Add IFLA_BOND_XMIT_HASH_POLICY to allow get/set of bonding parameter
xmit_hash_policy via netlink.

Signed-off-by: Scott Feldman <sfeldma@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
index fd181ab..1a5d394 100644
--- a/include/uapi/linux/if_link.h
+++ b/include/uapi/linux/if_link.h
@@ -342,6 +342,7 @@
 	IFLA_BOND_PRIMARY,
 	IFLA_BOND_PRIMARY_RESELECT,
 	IFLA_BOND_FAIL_OVER_MAC,
+	IFLA_BOND_XMIT_HASH_POLICY,
 	__IFLA_BOND_MAX,
 };