[RDKB][mt7986][app][Add L2TP and IPSec tools]

[Description]
Add L2TP and IPSec tools
1. upgrade the version of xl2tpd tool from 1.3.14 to 1.3.16
2. build in strongswan and xl2tpd tools for IPSec and L2TP

[Release-log]

diff --git a/recipes-connectivity/xl2tpd/xl2tpd_%.bbappend b/recipes-connectivity/xl2tpd/xl2tpd_%.bbappend
new file mode 100644
index 0000000..240adfd
--- /dev/null
+++ b/recipes-connectivity/xl2tpd/xl2tpd_%.bbappend
@@ -0,0 +1,4 @@
+SRC_URI_remove = "git://github.com/xelerance/xl2tpd.git"
+SRC_URI += "git://github.com/xelerance/xl2tpd.git;branch=master;protocol=https"
+SRCREV = "1ef2a025981223c1e16fc833bef226c86ff8c295"
+UPSTREAM_CHECK_URI = "https://github.com/xelerance/xl2tpd/releases"
\ No newline at end of file
diff --git a/recipes-core/images/rdk-generic-broadband-image.bbappend b/recipes-core/images/rdk-generic-broadband-image.bbappend
index 8e2a56b..2dc7a06 100644
--- a/recipes-core/images/rdk-generic-broadband-image.bbappend
+++ b/recipes-core/images/rdk-generic-broadband-image.bbappend
@@ -18,6 +18,8 @@
     dosfstools \
     pptp-linux \
     rp-pppoe  \  
+    xl2tpd \
+    strongswan \  
     "
 #IMAGE_INSTALL += " opensync openvswitch mesh-agent e2fsprogs "