ath79-generic: (re)add support for UniFi AP LR

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

docs/user/supported_devices.rst

@@ -57,6 +57,7 @@ ath79-generic
 * Ubiquiti
 
   - UniFi AP
+  - UniFi AP LR
 
 ath79-nand
 ----------

targets/ath79-generic

@@ -139,6 +139,9 @@ device('tp-link-wbs210-v2', 'tplink_wbs210-v2')
 -- Ubiquiti
 
 device('ubiquiti-unifi-ap', 'ubnt_unifi', {
+	aliases = {
+		'ubiquiti-unifi-ap-lr',
+	},
 	manifest_aliases = {
 		'ubiquiti-unifi',
 	},