due to some changes in bluez / bluetoothctl, `pairable on` is required
in order to create a `[LinkKey]` section in the configuration file for
the connected device. if this section is missing, the device / gamepad
will not pair after being disconnect and has to be repaired again.
Pressing the START button removes the device pairing. Useful in case
the device (e.g. gamepad) was paired with a different adapter/computer
and needs to be paired again with current adapter/computer.
To pair again, RetroArch needs to be restarted, so the device list is
populated again.
Upstream of patch used by Lakka at build time
1943ad296e/packages/libretro/retroarch/patches/retroarch-98-remove_bluetooth_pairing.patch
