Add missing include guards and use generic transport include

Author: sandeepmistry

src/utility/HCI.cpp

@@ -18,7 +18,7 @@
 */
 
 #include "ATT.h"
-#include "HCIUartTransport.h"
+#include "HCITransport.h"
 #include "L2CAPSignaling.h"
 
 #include "HCI.h"

src/utility/HCITransport.h

@@ -17,6 +17,9 @@
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
+#ifndef _HCI_TRANSPORT_INTERFACE_H_
+#define _HCI_TRANSPORT_INTERFACE_H_
+
 #include <Arduino.h>
 
 class HCITransportInterface {
@@ -34,3 +37,5 @@ class HCITransportInterface {
 };
 
 extern HCITransportInterface& HCITransport;
+
+#endif

src/utility/HCIUartTransport.h

@@ -17,6 +17,9 @@
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */
 
+#ifndef _HCI_UART_TRANSPORT_H_
+#define _HCI_UART_TRANSPORT_H_
+
 #include "HCITransport.h"
 
 class HCIUartTransportClass : public HCITransportInterface {
@@ -39,3 +42,5 @@ class HCIUartTransportClass : public HCITransportInterface {
   HardwareSerial* _uart;
   unsigned long _baudrate;
 };
+
+#endif