ar71xx: add support for TP-Link TL-MR3020

This patch adds support for the TP-Link device TL-MR3020 which is very
similiar to the TL-WR703N.
The TL-MR3020 uses 5 LEDs, 1 push button and a switch with 3 positions.
Only four LEDs can be controlled via GPIO. The power LED is connected to
the power supply.
The WPS push button has been mapped to KEY_WPS_BUTTON. The two GPIO signals
of the sliding switch have been mapped to BTN_0 and BTN_1.

I have also setup a wiki page with details here:
http://wiki.openwrt.org/toh/tp-link/tl-mr3020

USB is working and has been tested with USB mass storage and USB UMTS
stick.

Wifi also seems to work.

Ethernet is working too.

Signed-off-by: Christian Cier-Zniewski <c.cier@gmx.de>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@29651 3c298f89-4303-0410-b956-a3cf2f4a3e73

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

@@ -94,6 +94,9 @@ tplink_board_detect() {
 	"104300"*)
 		model="TP-Link TL-WR1043N/ND"
 		;;
+	"302000"*)
+		model="TP-Link TL-MR3020"
+		;;
 	"322000"*)
 		model="TP-Link TL-MR3220"
 		;;
@@ -238,6 +241,9 @@ ar71xx_board_detect() {
 	*"DIR-615 rev. C1")
 		name="dir-615-c1"
 		;;
+	*TL-MR3020)
+		name="tl-mr3020"
+		;;
 	*TL-MR3220)
 		name="tl-mr3220"
 		;;

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

@@ -119,6 +119,7 @@ platform_check_image() {
 		}
 		return 0
 		;;
+	tl-mr3020 | \
 	tl-mr3220 | \
 	tl-mr3420 | \
 	tl-wa901nd | \