ramips: fix Archer C20i wireless MAC address

The TP-Link Archer C20i previously had a generic Ralink MAC address set
for both radios, as the caldata does only contain a generic MAC address.

Set the MAC address from the vendor firmware for both radios to assign
unique MAC addresses to every device.

Signed-off-by: David Bauer <mail@david-bauer.net>
(cherry picked from commit 3b013dcdf8)

target/linux/ramips/dts/ArcherC20i.dts

@@ -152,6 +152,7 @@
 
 &wmac {
 	ralink,mtd-eeprom = <&radio 0>;
+	mtd-mac-address = <&rom 0xf100>;
 };
 
 &pcie {
@@ -163,5 +164,7 @@
 		reg = <0x0000 0 0 0 0>;
 		mediatek,mtd-eeprom = <&radio 32768>;
 		ieee80211-freq-limit = <5000000 6000000>;
+		mtd-mac-address = <&rom 0xf100>;
+		mtd-mac-address-increment = <(-1)>;
 	};
 };