ath79: fix TPLINK_HWREV field for TL-WR1043ND v4

Required to allow sysupgrades from OpenWrt 19.07.

Closes openwrt#7071

Fixes: 98fbf2e ("ath79: move TPLINK_HWID/_HWREV to parent for tplink-safeloader")
Tested-by: J. Burfeind <git@aiyionpri.me>
Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

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

@@ -711,6 +711,7 @@ define Device/tplink_tl-wr1043nd-v4
   DEVICE_VARIANT := v4
   DEVICE_PACKAGES := kmod-usb2 kmod-usb-ledtrig-usbport
   TPLINK_HWID := 0x10430004
+  TPLINK_HWREV := 0x1
   TPLINK_BOARD_ID := TLWR1043NDV4
   SUPPORTED_DEVICES += tl-wr1043nd-v4
 endef