ssp1_set_mode_max2837()/void ssp1_set_mode_max5864(void) SPI speed updated to 4.857MHz instead of 0.0498MHz
To do test it to check there is no problem.
Adding "sample_rate_hz" option, Ctrl C exit shall be fixed with also minor fix in hackrf lib (manage do_exit in thread).
Need more test on linux.