boards: arm: stm32: add pinctrl state name for PWM peripheral

Add the pinctrl state name (default) for the PWM peripherals.
Changes performed based on the script proposed in
"boards: arm: stm32: add pinctrl state name for UART peripheral"

Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
diff --git a/boards/arm/nucleo_l432kc/nucleo_l432kc.dts b/boards/arm/nucleo_l432kc/nucleo_l432kc.dts
index 5ef50d8..a073c40 100644
--- a/boards/arm/nucleo_l432kc/nucleo_l432kc.dts
+++ b/boards/arm/nucleo_l432kc/nucleo_l432kc.dts
@@ -88,6 +88,7 @@
 	pwm2: pwm {
 		status = "okay";
 		pinctrl-0 = <&tim2_ch1_pa0>;
+		pinctrl-names = "default";
 	};
 };