ramips: fix Mercury MAC1200R v2.0 board name

With d2b6bf1416 ("ramips: fix image validation errors") the board
name was changed to fix an image validation error. But this change
wasn't applied to all other files using the board name, which broke
sysupgrade.

Revert this change and use the former board name in the metadata
instead.

Signed-off-by: Mathias Kresin <dev@kresin.me>

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

@@ -290,7 +290,7 @@ ramips_board_detect() {
 		name="m2m"
 		;;
 	*"Mercury MAC1200R v2")
-		name="mac1200r-v2"
+		name="mac1200rv2"
 		;;
 	*"MicroWRT")
 		name="microwrt"

target/linux/ramips/image/mt7628.mk

@@ -92,6 +92,7 @@ TARGET_DEVICES += duzun-dm06
 define Device/mac1200r-v2
   DTS := MAC1200RV2
   DEVICE_TITLE := Mercury MAC1200R v2.0
+  SUPPORTED_DEVICES := mac1200rv2
 endef
 TARGET_DEVICES += mac1200r-v2