arm64: dts: imx8mq-librem5: Set vibrator's PWM frequency to 20kHz

1Hz as used previously was way too long.

Signed-off-by: Sebastian Krzyszkowiak <sebastian.krzyszkowiak@puri.sm>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Author: dos1

arch/arm64/boot/dts/freescale/imx8mq-librem5.dtsi

@@ -287,7 +287,7 @@
 
 	vibrator {
 		compatible = "pwm-vibrator";
-		pwms = <&pwm1 0 1000000000 0>;
+		pwms = <&pwm1 0 50000 0>;
 		pwm-names = "enable";
 		vcc-supply = <&reg_vdd_3v3>;
 	};