fix STR bugs and improve code

- Reset reply size after returning a reply
- Reset data link layer and flush RX for regular commands and before
  performing special commands to ensure consistent start state
- Clean up DHB a bit
- Set STR dev to OFF in assembly when it is faulty.

linux/acs/StrComHandler.h

@@ -374,6 +374,8 @@ class StrComHandler : public SystemObject, public DeviceCommunicationIF, public
    * @return
    */
   ReturnValue_t readOneReply(uint32_t failParameter);
+
+  void resetReplyHandlingState();
 };
 
 #endif /* BSP_Q7S_DEVICES_STRHELPER_H_ */