patch leds: pwm: silently error out on EPROBE_DEFER

Hi,

please pick commit 9aec30371fb095a0c9415f3f0146ae269c3713d8 (leds: pwm: silently error out on EPROBE_DEFER) from the 4.20 release to the stable LTS version 4.19.

I own a Odroid HC1 and run Debian testing (with kernel 4.19) on it. It produces these kernel warnings:

[ 14.718000] leds_pwm pwmleds: unable to request PWM for blue:heartbeat: -517 [ 14.752948] leds_pwm pwmleds: unable to request PWM for blue:heartbeat: -517 [ 14.771394] leds_pwm pwmleds: unable to request PWM for blue:heartbeat: -517 [ 14.799319] leds_pwm pwmleds: unable to request PWM for blue:heartbeat: -517

These messages were misleading me thinking that the blue heartbeat LED isn't work (it works, but it is off by default).