arm64: dts: mt7622: handle interrupts from MT7531 switch on BPI-R64

Since commit ba751e28 ("net: dsa: mt7530: add interrupt support")
the mt7530 driver can act as an interrupt controller. Wire up irq line
of the MT7531 switch on the BananaPi BPi-R64 board, so the status of
the PHYs of the five 1000Base-T ports doesn't need to be polled any
more.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://lore.kernel.org/r/ZEA-DV_OsmFg5egL@makrotopia.orgSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>

arch/arm64/boot/dts/mediatek/mt7622-bananapi-bpi-r64.dts

@@ -150,6 +150,10 @@ mdio: mdio-bus {
 		switch@0 {
 			compatible = "mediatek,mt7531";
 			reg = <0>;
+			interrupt-controller;
+			#interrupt-cells = <1>;
+			interrupt-parent = <&pio>;
+			interrupts = <53 IRQ_TYPE_LEVEL_HIGH>;
 			reset-gpios = <&pio 54 0>;
 
 			ports {