Fix: Add explicit includes for assert.h and thread in sample files (#751)

* Fix: Add explicit includes for assert.h and thread in sample/vcopy.cpp

The HIP/CLR change e3cb5399c removed transitive inclusion  
of standard headers like assert.h from hip_runtime.h.  
This caused build failures in rocprof-compute samples.  

This commit explicitly includes <assert.h> and <thread>  
in vcopy.cpp to resolve potential missing definitions.  


Signed-off-by: jamessiddeley-amd <James.Siddeley@amd.com>

* Update vsequential_access.cpp

Added assert and thread imports

Signed-off-by: jamessiddeley-amd <James.Siddeley@amd.com>

* Update vrandom_access.cpp

Added assert import

Signed-off-by: jamessiddeley-amd <James.Siddeley@amd.com>

* Update vsequential_access.cpp

Signed-off-by: jamessiddeley-amd <James.Siddeley@amd.com>

---------

Signed-off-by: jamessiddeley-amd <James.Siddeley@amd.com>

sample/vcopy.cpp

@@ -25,6 +25,8 @@
 */
 
 #include "hip/hip_runtime.h"
+#include <assert.h>
+#include <thread>
 #include <stdio.h>
 #include <stdlib.h>
 #include <math.h>