Cellular: fixed to compile even if CELLULAR_DEVICE and rx/tx are not defined.

features/cellular/framework/API/CellularDevice.h

@@ -33,6 +33,10 @@ class FileHandle;
 const int MAX_PIN_SIZE = 8;
 const int MAX_PLMN_SIZE = 16;
 
+#ifndef MBED_CONF_NSAPI_DEFAULT_CELLULAR_APN
+#define MBED_CONF_NSAPI_DEFAULT_CELLULAR_APN NULL
+#endif
+
 /**
  *  Class CellularDevice
  *

features/cellular/framework/AT/AT_CellularDevice.cpp

@@ -33,6 +33,18 @@ using namespace mbed;
 
 #define DEFAULT_AT_TIMEOUT 1000 // at default timeout in milliseconds
 
+#ifndef MDMTXD
+#define MDMTXD NC
+#endif
+
+#ifndef MDMRXD
+#define MDMRXD NC
+#endif
+
+#ifndef MBED_CONF_PLATFORM_DEFAULT_SERIAL_BAUD_RATE
+#define MBED_CONF_PLATFORM_DEFAULT_SERIAL_BAUD_RATE 115200
+#endif
+
 AT_CellularDevice::AT_CellularDevice(EventQueue &queue) :
     _atHandlers(0), _network(0), _sms(0), _sim(0), _power(0), _information(0), _context_list(0), _at_queue(queue),
     _default_timeout(DEFAULT_AT_TIMEOUT), _modem_debug_on(false)