ramips/mt76x8: Name DTS files based on scheme

target/linux/ramips/dts/mt7628an_vocore_vocore2.dtsi

target/linux/ramips/dts/mt7628an_wavlink_wl-wn570ha1.dts

target/linux/ramips/dts/mt7628an_wavlink_wl-wn575a3.dts

target/linux/ramips/dts/mt7628an_widora_neo-16m.dts

target/linux/ramips/dts/mt7628an_widora_neo-32m.dts

target/linux/ramips/dts/mt7628an_widora_neo.dtsi

target/linux/ramips/dts/mt7628an_wiznet_wizfi630s.dts

target/linux/ramips/dts/mt7628an_wrtnode_wrtnode2.dtsi

target/linux/ramips/dts/mt7628an_wrtnode_wrtnode2p.dts

target/linux/ramips/dts/mt7628an_wrtnode_wrtnode2r.dts

target/linux/ramips/dts/mt7628an_xiaomi_mir4a-100m.dts

target/linux/ramips/dts/mt7628an_xiaomi_miwifi-nano.dts

target/linux/ramips/dts/mt7628an_zbtlink_zbt-we1226.dts

target/linux/ramips/dts/mt7628an_zyxel_keenetic-extra-ii.dts

target/linux/ramips/image/mt76x8.mk