tcl: add TP-LINK TL-MR3020 to the firmware recovery script

This adds the board to the list of supported devices for the easy
recovery procedure. Only ram_boot is supported for this target.

Change-Id: I144e1836f8b6257e96a42c98c2668da74ce243f6
Signed-off-by: Oleksij Rempel <linux@rempel-privat.de>
Reviewed-on: http://openocd.zylin.com/2520
Reviewed-by: Paul Fertser <fercerpav@gmail.com>
Tested-by: jenkins
Reviewed-by: Andreas Färber <afaerber@suse.de>

tcl/tools/firmware-recovery.tcl

@@ -6,6 +6,7 @@ set known_boards {
     "asus-rt-n66u		ASUS RT-N66U"
     "linksys-wrt54gl		Linksys WRT54GL v1.1"
     "netgear-dg834v3		Netgear DG834G v3"
+    "tp-link_tl-mr3020		TP-LINK TL-MR3020"
     "bt-homehubv1		BT HomeHub v1"
 }