ath79-generic: (re)add support for glinet_6416 (#2453)

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

docs/user/supported_devices.rst

@@ -32,6 +32,7 @@ ath79-generic
 
 * GL.iNet
 
+  - 6416A
   - GL-AR150
   - GL-AR300M-Lite
   - GL-AR750

targets/ath79-generic

@@ -93,6 +93,13 @@ device('enterasys-ws-ap3705', 'enterasys_ws-ap3705i', {
 
 -- GL.iNet
 
+device('gl.inet-6416', 'glinet_6416', {
+	factory = false,
+	manifest_aliases = {
+		'gl-inet-6416a-v1', -- Upgrade from OpenWrt 19.07
+	},
+})
+
 device('gl.inet-gl-ar150', 'glinet_gl-ar150', {
 	factory = false,
 })