ar71xx: add support for TP-Link TL-WDR6500 v2

Signed-off-by: Weijie Gao <hackpascal@gmail.com>

This patch adds support for TP-Link TL-WDR6500 v2.

The firmware has a U-Boot header for kernel, and a TP-LINK v2 header for
the whole firmware, so I have to create a new firmware creation method.

SVN-Revision: 46663

target/linux/ar71xx/base-files/lib/upgrade/platform.sh

@@ -341,6 +341,7 @@ platform_check_image() {
 	tl-wdr3500 | \
 	tl-wdr4300 | \
 	tl-wdr4900-v2 | \
+	tl-wdr6500-v2 | \
 	tl-wr703n | \
 	tl-wr710n | \
 	tl-wr720n-v3 | \
@@ -358,7 +359,15 @@ platform_check_image() {
 	tl-wr1043nd | \
 	tl-wr1043nd-v2 | \
 	tl-wr2543n)
-		[ "$magic" != "0100" ] && {
+		local magic_ver="0100"
+
+		case "$board" in
+		tl-wdr6500-v2)
+			magic_ver="0200"
+			;;
+		esac
+
+		[ "$magic" != "$magic_ver" ] && {
 			echo "Invalid image type."
 			return 1
 		}