ath79: Add SUPPORTED_DEVICES for Archer C7 v1/v2

The identifier for both devices is "archer-c7" on ar71xx, set here:
https://github.com/openwrt/openwrt/blob/master/target/linux/ar71xx/base-files/lib/ar71xx.sh#L348
https://github.com/openwrt/openwrt/blob/master/target/linux/ar71xx/base-files/lib/ar71xx.sh#L511

Signed-off-by: Adrian Schmutzler <[email protected]>

target/linux/ath79/image/generic-tp-link.mk

@@ -81,6 +81,7 @@ define Device/tplink_archer-c7-v1
   DEVICE_TITLE := TP-Link Archer C7 v1
   DEVICE_PACKAGES := kmod-usb-core kmod-usb2 kmod-usb-ledtrig-usbport kmod-ath10k-ct ath10k-firmware-qca988x-ct
   TPLINK_HWID := 0x75000001
+  SUPPORTED_DEVICES += archer-c7
 endef
 TARGET_DEVICES += tplink_archer-c7-v1
 
@@ -90,6 +91,7 @@ define Device/tplink_archer-c7-v2
   DEVICE_TITLE := TP-Link Archer C7 v2
   DEVICE_PACKAGES := kmod-usb-core kmod-usb2 kmod-usb-ledtrig-usbport kmod-ath10k-ct ath10k-firmware-qca988x-ct
   TPLINK_HWID := 0xc7000002
+  SUPPORTED_DEVICES += archer-c7
   IMAGES += factory-us.bin factory-eu.bin
   IMAGE/factory-us.bin := append-rootfs | mktplinkfw factory -C US
   IMAGE/factory-eu.bin := append-rootfs | mktplinkfw factory -C EU