support hardware PWM for controlling LEDs

[morris2009]

Hi,
it would be very nice if there was support for hardware PWM to be able to control LED's in a much higher frequency so there is no flickering.
hardware PWM is supported on the RPI, and i tried enabling the hardware PWM overlay for GPIO18 in /boot/config.txt, but Octoprint-Enclosure then wasn't able to control that pin anymore.

There are other plugins that are much more minimalistic that are now able to do this, but they lack all the other nice features that OctoPrint-Enclosure has.
It would be nice to be able to use this.

[ahmaddxb]

Try my fork i have implement Hardware pwm

https://github.com/ahmaddxb/OctoPrint-Enclosure