[dtests] Disable hip_threadfence_system.tst on nvcc

The test needs some more modifications before it is ready for building
on nvcc path. Disabling it for now so that the pull request can be
merged.

Change-Id: I19a894fcda7b2159f86a4e4e95a409c5655d3760

hipamd/tests/src/deviceLib/hip_threadfence_system.cpp

@@ -21,7 +21,7 @@ THE SOFTWARE.
 */
 
 /* HIT_START
- * BUILD: %t %s ../test_common.cpp
+ * BUILD: %t %s ../test_common.cpp EXCLUDE_HIP_PLATFORM nvcc
  * RUN: %t
  * HIT_END
  */