exclude tx and rx if CYW43XXX_UNBUFFERED_UART is defined

Author: pennam

connectivity/drivers/ble/FEATURE_BLE/COMPONENT_CYW43XXX/CyH4TransportDriver.h

@@ -102,9 +102,9 @@ class CyH4TransportDriver : public CordioHCITransportDriver {
     mbed::UnbufferedSerial uart;
 #else
     cyhal_uart_t uart;
-#endif
     PinName tx;
     PinName rx;
+#endif
     PinName cts;
     PinName rts;
     PinName bt_host_wake_name;