[FEATURE] RPi4B audio jack support over PWM

[linguini1]

Is your feature request related to a problem? Please describe.

The RPi4B has an audio jack accessible via PWM1 output. It would be good to support audio output over this.

Describe the solution you'd like

Audio jack output working.

Describe alternatives you've considered

No response

Verification

• I have verified before submitting the report.

[linguini1]

Example:

https://github.com/sypstraw/rpi4-osdev/blob/master/part9-sound/kernel.c