While the modem has worked for quite a while on mainline, for some reason some dependencies were never added to the device package. And add the firmware for the audio amplifier on Fairphone 3 since it's also supposed to work now. And install qbootctl (and enable it by default) to mark the current slot as successful to not get stuck in the bootloader after a couple of reboots. Part-of: <https://gitlab.postmarketos.org/postmarketOS/pmaports/-/merge_requests/7010>