dt-bindings: irq: mtk, sysirq: add support for mt6779

Add binding documentation of mediatek,sysirq for mt6779 SoC.
Signed-off-by: Mars Cheng <mars.cheng@mediatek.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

Documentation/devicetree/bindings/interrupt-controller/mediatek,sysirq.txt

@@ -15,6 +15,7 @@ Required properties:
 	"mediatek,mt7629-sysirq", "mediatek,mt6577-sysirq": for MT7629
 	"mediatek,mt6795-sysirq", "mediatek,mt6577-sysirq": for MT6795
 	"mediatek,mt6797-sysirq", "mediatek,mt6577-sysirq": for MT6797
+	"mediatek,mt6779-sysirq", "mediatek,mt6577-sysirq": for MT6779
 	"mediatek,mt6765-sysirq", "mediatek,mt6577-sysirq": for MT6765
 	"mediatek,mt6755-sysirq", "mediatek,mt6577-sysirq": for MT6755
 	"mediatek,mt6592-sysirq", "mediatek,mt6577-sysirq": for MT6592