ARM: dts: lpc32xx: set default parent clock for pwm1 & pwm2

The change setup the peripheral clock (PERIPH_CLK) as the default
parent clock for PWM1 & PWM2.
Signed-off-by: Sylvain Lemieux <slemieux@tycoint.com>
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>

arch/arm/boot/dts/lpc32xx.dtsi

@@ -479,6 +479,8 @@ pwm1: pwm@4005C000 {
 				compatible = "nxp,lpc3220-pwm";
 				reg = <0x4005C000 0x4>;
 				clocks = <&clk LPC32XX_CLK_PWM1>;
+				assigned-clocks = <&clk LPC32XX_CLK_PWM1>;
+				assigned-clock-parents = <&clk LPC32XX_CLK_PERIPH>;
 				status = "disabled";
 			};
 
@@ -486,6 +488,8 @@ pwm2: pwm@4005C004 {
 				compatible = "nxp,lpc3220-pwm";
 				reg = <0x4005C004 0x4>;
 				clocks = <&clk LPC32XX_CLK_PWM2>;
+				assigned-clocks = <&clk LPC32XX_CLK_PWM2>;
+				assigned-clock-parents = <&clk LPC32XX_CLK_PERIPH>;
 				status = "disabled";
 			};