Correct HIP_FUNC_ATTRIBUTE_MAX_THREADS_PER_BLOCK query

We should be returning the max workgroup size calculated by the compiler.

Change-Id: If86590efbb9b291f470bdbe87e5df992e661c539


[ROCm/clr commit: b5f9d2f818]

projects/clr/hipamd/rocclr/hip_platform.cpp

@@ -313,7 +313,7 @@ bool ihipGetFuncAttributes(const char* func_name, amd::Program* program, hipFunc
   func_attr->localSizeBytes = wginfo->privateMemSize_;
   func_attr->sharedSizeBytes = wginfo->localMemSize_;
   func_attr->maxDynamicSharedSizeBytes = wginfo->availableLDSSize_ - wginfo->localMemSize_;
-  func_attr->maxThreadsPerBlock = wginfo->wavefrontSize_;
+  func_attr->maxThreadsPerBlock = wginfo->size_;
   func_attr->numRegs = wginfo->usedVGPRs_;
 
   return true;