disabled half native support as inline asm is not working

Change-Id: I3073d8ae39eed321987f0f2f0e689eec4cdbb48c


[ROCm/clr commit: c673aec971]

projects/clr/hipamd/include/hip/hcc_detail/hip_fp16.h

@@ -25,9 +25,7 @@ THE SOFTWARE.
 
 #include "hip/hip_runtime.h"
 
-#define __CLANG_VERSION__ __clang_major__ * 10 + __clang_minor__
-
-#ifdef HIP_HALF_HW_SUPPORT
+#if 0
 
 typedef __fp16 __half;