Add SAI_OBJECT_TYPE_TUNNEL object to break-before-make list (#1075)

SAI_OBJECT_TYPE_TUNNEL has fewer attributes in 201811 than in 202012. These new attributes are CREATE only, and can't be added using just SET oper. Hence old object needs to be removed, and new object needs to be added.
Moreover existing sequence (make before break) causes SAI errors in removing VXLAN tunnel (as part of CPA teardown).

Adding SAI_OBJECT_TYPE_TUNNEL to break before make to avoid creating a new object before removing existing ones.

syncd/scripts/syncd_init_common.sh

@@ -175,6 +175,7 @@ config_syncd_bcm()
     fi
 
     echo "SAI_OBJECT_TYPE_ACL_TABLE" >> /tmp/break_before_make_objects
+    echo "SAI_OBJECT_TYPE_TUNNEL" >> /tmp/break_before_make_objects
     CMD_ARGS+=" -b /tmp/break_before_make_objects"
 
     [ -e /dev/linux-bcm-knet ] || mknod /dev/linux-bcm-knet c 122 0