[qca-nss-sfe] Add support for Tun6rd handling

Create IPv4 outer rule acceleration.

Change-Id: I0116c8c9d86208cf27908ffbba1f7eeeed08a8ae
Signed-off-by: Tian Yang <quic_tiany@quicinc.com>
diff --git a/sfe_ipv4_tun6rd.h b/sfe_ipv4_tun6rd.h
new file mode 100644
index 0000000..bfa7cc0
--- /dev/null
+++ b/sfe_ipv4_tun6rd.h
@@ -0,0 +1,22 @@
+/*
+ * sfe_ipv4_tun6rd.h
+ *	Shortcut forwarding engine header file for IPv4 TUN6RD
+ *
+ * Copyright (c) 2022 Qualcomm Innovation Center, Inc. All rights reserved.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+int sfe_ipv4_recv_tun6rd(struct sfe_ipv4 *si, struct sk_buff *skb, struct net_device *dev,
+			     unsigned int len, struct iphdr *iph, unsigned int ihl,
+				bool sync_on_find, struct sfe_l2_info *l2_info, bool tun_outer);