ath79-generic: (re)add wzr-hp-ag-300h / wzr-600dhp (#2515)

Both are effectively the same hardware, the latter being Buffalos
replacement model.

Gone due to
commit 45c84a11 ("ar71xx: drop target")

docs/user/supported_devices.rst

@@ -9,6 +9,10 @@ ath79-generic
   - Fritz!WLAN Repeater 450E [#avmflash]_
   - Fritz!Box 4020 [#avmflash]_
 
+* Buffalo
+
+  - WZR-HP-AG300H / WZR-600DHP
+
 * devolo
 
   - WiFi pro 1200e [#lan_as_wan]_

targets/ath79-generic

@@ -26,6 +26,11 @@ device('avm-fritz-wlan-repeater-450e', 'avm_fritz450e', {
 	factory = false,
 })
 
+-- Buffalo
+
+device('buffalo-wzr-hp-ag300h', 'buffalo_wzr-hp-ag300h')
+device('buffalo-wzr-600dhp', 'buffalo_wzr-600dhp')
+
 -- devolo
 
 device('devolo-wifi-pro-1200e', 'devolo_dvl1200e', {