[C61] add PWM buzzer support

arch/arm64/boot/dts/seco/seco-imx8mm-c61.dts

@@ -22,6 +22,19 @@
 		reg = <0x0 0x40000000 0 0x80000000>;
 	};
 
+	buzzer {
+		compatible    = "pwm-generic";
+		pwms          = <&pwm2 0 500000000>;
+		pinctrl-0     = <&pinctrl_pwm2_out>;
+		max-duty      = <255>;
+		dft-duty      = <128>;
+		pwm-period-ns = <5000000>;
+		period-ns-min = <150>;
+		period-ns-max = <50000000>;
+		pwm-id        = <1>;
+		enable        = <0>;
+	};
+
 	pcie0_refclk: pcie0-refclk {
 		compatible = "fixed-clock";
 		#clock-cells = <0>;