Fixes for P2P and hipDeviceReset

- devicereset would lose track of default stream and thus subsequent
  synchronization calls might not actually sychronize.
- Also deviceReset now correctly frees streams.
- fix waits in P2P staging copy - first phase (Device0-to-Staging) must
  wait for second phase (Staging to Device1) to finish draining the
  buffer.

src/hip_device.cpp

@@ -172,12 +172,6 @@ hipError_t hipDeviceReset(void)
 
 
     if (device) {
-        //---
-        //Wait for pending activity to complete?  TODO - check if this is required behavior:
-        //TODO, also we have small window between wait and reset.
-        
-        device->locked_waitAllStreams();
-
         // Release device resources (streams and memory):
         device->locked_reset(); 
     }