changed __half enabling from 4 to >3

Change-Id: Id974c6d5326e87a4c5941f831c5bb2747cdebd2d


[ROCm/clr commit: 37bc29e44b]

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

@@ -25,7 +25,7 @@ THE SOFTWARE.
 
 #include "hip/hip_runtime.h"
 
-#if __clang_major__ == 4
+#if __clang_major__ > 3
 
 typedef __fp16 __half;