GPIO Pullups on RPi4 (mk_arcade_joystick_rpi driver) - PR

[Lolonois]

Thanks @mitu for reviving the mk_arcade_joystick_rpi driver for retropie after digitallumberjack went away from this project.

I filed two PR (retropie-hotkeybtn, retropie) to make the driver compliant with the pullup logic on the BCM 2711 used in the RPi4.

Tested the retropie and retropie-hotkey branch with the PR against:
RPi3B, RPi4B and GPIO only as well as with MCP23017

Cheers

[mitu]

Appreciated, thank you.

I've merged those 2 PRs and tagged other users that might be interested Pi 4 compatibility/support.