This adds a IPC backend that uses shared memory interface
to communicate with (proprietary) devices.
Requires config file option
dev-args ipc_msock=/path/to/socket
to specify the master socket the ipc backend should connect to.
If UHD is avaialble the ipc-driver-test tool can be used to test the
backend with a uhd device, this was so far only tested with a b2xx.
Change-Id: Ice63d3499026293ade8aad675ff7a883bcdd5756
Vadim Yanitskiy
Pau Espin Pedrol
Harald Welte
Eric Wild