ramips: use generic board detection for Unielec u7621-06

Use the generic board detection for the board instead of the target
specific one. Mark the sysupgrade image compatible with the former used
userspace boardname to allow an upgrade from earlier versions.

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

target/linux/ramips/base-files/etc/board.d/02_network

@@ -115,7 +115,7 @@ ramips_setup_interfaces()
 	rt-n12p|\
 	sap-g3200u3|\
 	sk-wb8|\
-	u7621-06-256M-16M|\
+	unielec,u7621-06-256m-16m|\
 	vr500|\
 	wavlink,wl-wn570ha1|\
 	wf-2881|\

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

@@ -502,9 +502,6 @@ ramips_board_detect() {
 	*"U25AWF-H1")
 		name="u25awf-h1"
 		;;
-	*"U7621-06 (256M RAM/16M flash)")
-		name="u7621-06-256M-16M"
-		;;
 	*"U7628-01 (128M RAM/16M flash)")
 		name="u7628-01-128M-16M"
 		;;

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

@@ -162,7 +162,7 @@ platform_check_image() {
 	timecloud|\
 	tiny-ac|\
 	u25awf-h1|\
-	u7621-06-256M-16M|\
+	unielec,u7621-06-256m-16m|\
 	u7628-01-128M-16M|\
 	ur-326n4g|\
 	ur-336un|\

target/linux/ramips/image/mt7621.mk

@@ -366,14 +366,6 @@ define Device/timecloud
 endef
 TARGET_DEVICES += timecloud
 
-define Device/u7621-06-256M-16M
-  DTS := U7621-06-256M-16M
-  IMAGE_SIZE := 16064k
-  DEVICE_TITLE := UniElec U7621-06 (256M RAM/16M flash)
-  DEVICE_PACKAGES := kmod-ata-core kmod-ata-ahci kmod-sdhci-mt7620 kmod-usb3
-endef
-TARGET_DEVICES += u7621-06-256M-16M
-
 define Device/ubnt-erx
   DTS := UBNT-ERX
   FILESYSTEMS := squashfs
@@ -394,6 +386,15 @@ define Device/ubnt-erx-sfp
 endef
 TARGET_DEVICES += ubnt-erx-sfp
 
+define Device/unielec_u7621-06-256m-16m
+  DTS := U7621-06-256M-16M
+  IMAGE_SIZE := 16064k
+  DEVICE_TITLE := UniElec U7621-06 (256M RAM/16M flash)
+  DEVICE_PACKAGES := kmod-ata-core kmod-ata-ahci kmod-sdhci-mt7620 kmod-usb3
+  SUPPORTED_DEVICES += u7621-06-256M-16M
+endef
+TARGET_DEVICES += unielec_u7621-06-256m-16m
+
 define Device/vr500
   DTS := VR500
   IMAGE_SIZE := 66453504