ramips/mt76x8: Name DTS files based on scheme

Signed-off-by: Adrian Schmutzler <freifunk@adrianschmutzler.de>

target/linux/ramips/dts/OMEGA2.dts → target/linux/ramips/dts/mt7628an_onion_omega2.dts

 /dts-v1/;
 
-#include "OMEGA2.dtsi"
+#include "mt7628an_onion_omega2.dtsi"
 
 / {
 	compatible = "onion,omega2", "mediatek,mt7628an-soc";

target/linux/ramips/dts/OMEGA2P.dts → target/linux/ramips/dts/mt7628an_onion_omega2p.dts

 /dts-v1/;
 
-#include "OMEGA2.dtsi"
+#include "mt7628an_onion_omega2.dtsi"
 
 / {
 	compatible = "onion,omega2p", "onion,omega2", "mediatek,mt7628an-soc";