arm64: dts: ti: k3-am64-mcu: Add pinctrl

Add the definition of the pinctrl for the MCU domain.
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Reviewed-by: Dave Gerlach <d-gerlach@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20210818111747.88569-1-christian.gmeiner@gmail.com

arch/arm64/boot/dts/ti/k3-am64-mcu.dtsi

@@ -97,4 +97,12 @@ mcu_gpio0: gpio@4201000 {
 		clocks = <&k3_clks 79 0>;
 		clock-names = "gpio";
 	};
+
+	mcu_pmx0: pinctrl@4084000 {
+		compatible = "pinctrl-single";
+		reg = <0x00 0x4084000 0x00 0x84>;
+		#pinctrl-cells = <1>;
+		pinctrl-single,register-width = <32>;
+		pinctrl-single,function-mask = <0xffffffff>;
+	};
 };