MLK-16131 arm64: dts: freescale: imx8mq: disable pwm led for over-drive mode

MLK-16131 arm64: dts: freescale: imx8mq: disable pwm led for over-drive mode

On i.MX8MQ EVK A1 board, GPIO1_IO13 pin is shared between
GPIO regulator and PWM2, when using over-drive dtb, there
will be no PWM2 function, disable PWM LED to avoid below
message during suspend/resume test:

[   19.754862] PM: resume of devices complete after 118.732 msecs
[   19.761740] Restarting tasks ...
[   19.761741] leds_pwm pwmleds: unable to request PWM for PWM2: -517
[   19.773557] done.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>