This function set isn't really usable for real communication. Its main
purpose is to help with testing the firmware.
- tools/lib/driver.h (struct atrf_driver): added driver functions for
HardMAC access
- tools/include/atrf.h (atrf_rx_mode, atrf_rx, atrf_tx),
tools/lib/atrf.c: functions to enable/disable HardMAC mode and to
send/receive frames