* currently the code introduces new IOCTLs. I'm afraid this is a bad idea.
  -> Replace this with another interface, hints are welcome!
* Some missing data (marked with ###) needs to be added in the documentation
* Change (struct pi433_tx_cfg)->bit_rate to be a u32 so that we can support
    bit rates up to 300kbps per the spec.
  -> This configuration needs to be moved to sysfs instead of being done through
     IOCTL. Going forward, we need to port userspace tools to use sysfs instead
     of IOCTL and then we would delete IOCTL.