ARM: sun7i: dt: add pinmux configuration for the PWM

Add the pinctrl descriptions for both PWM channels of the Allwinner A20.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

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

@@ -546,6 +546,20 @@ pio: pinctrl@01c20800 {
 			#size-cells = <0>;
 			#gpio-cells = <3>;
 
+			pwm0_pins_a: pwm0@0 {
+				allwinner,pins = "PB2";
+				allwinner,function = "pwm";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
+			pwm1_pins_a: pwm1@0 {
+				allwinner,pins = "PI3";
+				allwinner,function = "pwm";
+				allwinner,drive = <0>;
+				allwinner,pull = <0>;
+			};
+
 			uart0_pins_a: uart0@0 {
 				allwinner,pins = "PB22", "PB23";
 				allwinner,function = "uart0";