arm64: dts: mediatek: mt7986: Add SoC compatible

Missing SoC compatible in the board file causes dt bindings check.
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
Link: https://lore.kernel.org/r/20221114121653.14739-1-matthias.bgg@kernel.orgSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>

arch/arm64/boot/dts/mediatek/mt7986a-rfb.dts

@@ -9,7 +9,7 @@
 
 / {
 	model = "MediaTek MT7986a RFB";
-	compatible = "mediatek,mt7986a-rfb";
+	compatible = "mediatek,mt7986a-rfb", "mediatek,mt7986a";
 
 	aliases {
 		serial0 = &uart0;

arch/arm64/boot/dts/mediatek/mt7986a.dtsi

@@ -10,6 +10,7 @@
 #include <dt-bindings/reset/mt7986-resets.h>
 
 / {
+	compatible = "mediatek,mt7986a";
 	interrupt-parent = <&gic>;
 	#address-cells = <2>;
 	#size-cells = <2>;

arch/arm64/boot/dts/mediatek/mt7986b-rfb.dts

@@ -9,7 +9,7 @@
 
 / {
 	model = "MediaTek MT7986b RFB";
-	compatible = "mediatek,mt7986b-rfb";
+	compatible = "mediatek,mt7986b-rfb", "mediatek,mt7986b";
 
 	aliases {
 		serial0 = &uart0;

arch/arm64/boot/dts/mediatek/mt7986b.dtsi

@@ -5,6 +5,9 @@
  */
 
 #include "mt7986a.dtsi"
+/ {
+	compatible = "mediatek,mt7986b";
+};
 
 &pio {
 	compatible = "mediatek,mt7986b-pinctrl";