This patch adds support for both receiving and transmitting using
the FreeSRP. More information on the FreeSRP can be found at:
http://freesrp.org
The gr-osmosdr blocks added make use of libfreesrp, the library
required for interfacing with this device. The libfreesrp source
code is freely available at
https://github.com/freesrp/libfreesrp
Usage example:
osmocom_fft -a "freesrp"