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/radioDevice.h b/Transceiver52M/radioDevice.h
index 6d7ea72..a992483 100644
--- a/Transceiver52M/radioDevice.h
+++ b/Transceiver52M/radioDevice.h
@@ -35,10 +35,15 @@
   enum TxWindowType { TX_WINDOW_USRP1, TX_WINDOW_FIXED };
 
   /* Radio interface types */
-  enum RadioInterfaceType { NORMAL, RESAMP_64M, RESAMP_100M, DIVERSITY };
+  enum InterfaceType {
+    NORMAL,
+    RESAMP_64M,
+    RESAMP_100M,
+    DIVERSITY,
+  };
 
-  static RadioDevice *make(size_t tx_sps, size_t rx_sps = 1, size_t chans = 1,
-                           bool diversity = false, double offset = 0.0);
+  static RadioDevice *make(size_t tx_sps, size_t rx_sps, InterfaceType type,
+                           size_t chans = 1, double offset = 0.0);
 
   /** Initialize the USRP */
   virtual int open(const std::string &args = "", bool extref = false, bool swap_channels = false)=0;