radioInterface: Convert diversity argument to general type

Rather than a simple bool type, convert the diversity switch
to the device interface specifer:

  enum InterfaceType {
    NORMAL,
    RESAMP_64M,
    RESAMP_100M,
    DIVERSITY,
  };

The more general specifier allows passing in special cases
other then selection diversity such as multi-ARFCN support.

Signed-off-by: Tom Tsou <tom.tsou@ettus.com>
diff --git a/Transceiver52M/osmo-trx.cpp b/Transceiver52M/osmo-trx.cpp
index 241e69c..9dcda5f 100644
--- a/Transceiver52M/osmo-trx.cpp
+++ b/Transceiver52M/osmo-trx.cpp
@@ -437,6 +437,7 @@
 	RadioDevice *usrp;
 	RadioInterface *radio = NULL;
 	Transceiver *trx = NULL;
+	RadioDevice::InterfaceType iface = RadioDevice::NORMAL;
 	struct trx_config config;
 
 	handle_options(argc, argv, &config);
@@ -454,8 +455,8 @@
 	srandom(time(NULL));
 
 	/* Create the low level device object */
-	usrp = RadioDevice::make(config.tx_sps, config.rx_sps, config.chans,
-				 config.diversity, config.offset);
+	usrp = RadioDevice::make(config.tx_sps, config.rx_sps, iface,
+				 config.chans, config.offset);
 	type = usrp->open(config.dev_args, config.extref, config.swap_channels);
 	if (type < 0) {
 		LOG(ALERT) << "Failed to create radio device" << std::endl;