ralink: fix the compat string for mt7620a pci

Signed-off-by: John Crispin <blogic@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@43211 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/ramips/dts/mt7620a.dtsi

@@ -430,7 +430,7 @@
 	};
 
 	pcie@10140000 {
-		compatible = "ralink,mt7620-pci";
+		compatible = "mediatek,mt7620-pci";
 		reg = <0x10140000 0x100
 			0x10142000 0x100>;