ARM: sun7i: dt: add PWM support

Add the PWM bindings for the Allwinner A20.
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/boot/dts/sun7i-a20.dtsi

@@ -698,6 +698,14 @@
 			interrupts = <0 24 4>;
 		};
 
+		pwm: pwm@01c20e00 {
+			compatible = "allwinner,sun7i-a20-pwm";
+			reg = <0x01c20e00 0xc>;
+			clocks = <&osc24M>;
+			#pwm-cells = <3>;
+			status = "disabled";
+		};
+
 		sid: eeprom@01c23800 {
 			compatible = "allwinner,sun7i-a20-sid";
 			reg = <0x01c23800 0x200>;