ramips: fix GL-MT300N-V2 SoC compatible

According to abbfcc8525 ("ramips: add support for GL-inet
GL-MT300N-V2") the board has a MediaTek MT7628AN. Change the SoC
compatible to match the used hardware.

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/ramips/dts/GL-MT300N-V2.dts

@@ -6,7 +6,7 @@
 #include <dt-bindings/input/input.h>
 
 /{
-	compatible = "glinet,gl-mt300n-v2", "ralink,mt7620an-soc";
+	compatible = "glinet,gl-mt300n-v2", "mediatek,mt7628an-soc";
 	model = "GL-MT300N-V2";
 
 	aliases {