ipq40xx-generic: add AVM FRITZBox 7520 explicitely

AVM Fritz!Box 7520 and Fritz!Box 7530 use the same hardware platform and can
only be distinguished by using the urlader partition or the fritz-tffs tools
and read the ProductID (Fritz_Box_HW247).

(cherry picked from commit 5888a50c)

docs/user/supported_devices.rst

@@ -176,6 +176,7 @@ ipq40xx-generic
 * AVM
 
   - FRITZ!Box 4040 [#avmflash]_
+  - FRITZ!Box 7520 (v1) [#eva_ramboot]_
   - FRITZ!Box 7530 [#eva_ramboot]_
   - FRITZ!Repeater 1200 [#eva_ramboot]_
 

targets/ipq40xx-generic

@@ -58,6 +58,7 @@ device('avm-fritz-box-4040', 'avm_fritzbox-4040', {
 
 device('avm-fritz-box-7530', 'avm_fritzbox-7530', {
 	factory = false,
+	aliases = {'avm-fritz-box-7520'},
 })
 
 device('avm-fritz-repeater-1200', 'avm_fritzrepeater-1200', {