Refactor for building HIP as dynamic library

Change-Id: I65a3d9d589c4fdbbdcf1611e5427224253be8260

src/hip_memory.cpp

@@ -1037,7 +1037,3 @@ hipError_t hipFreeArray(hipArray* array)
     return ihipLogStatus(hipStatus);
 }
 
-
-__device__ void  __threadfence_system(void){
-    // no-op
-}