device-lenovo-21bx: various improvements

• usbguard config: these are builtin USB devices that should be allowed by default

• removed nonfree-fw package, I decided that everything from that should be required since some fairly major features are broken without these firmwares and relevant userspace apps

• re-enabled EFI runtime services, so efifb is used (and probably other benefits?)

  • Laptops need the "Linux Boot" option enabled
  • "With recent UEFI firmware efi=noruntime can be left out when the Linux Boot option is enabled."
  • https://github.com/jhovold/linux/wiki/X13s#kernel-command-line