SWDEV-434362 - Replace __HIP_CLANG_ONLY__ as it is not supported on HIPRTC

__HIP_CLANG_ONLY__ is not recognized in HIPRTC, due to which some
math functions like amd_mixed_dot were not included in hiprtc builtins.

Change-Id: I1fe41e1ddc8911f6a5b5b1405dd4730d0170a4f7

hipamd/include/hip/amd_detail/amd_device_functions.h

@@ -38,7 +38,7 @@ extern "C" __device__ int printf(const char *fmt, ...);
 #else
 template <typename... All>
 static inline __device__ void printf(const char* format, All... all) {}
-#endif // __HIP_CLANG_ONLY__
+#endif
 
 extern "C" __device__ unsigned long long __ockl_steadyctr_u64();
 

hipamd/include/hip/amd_detail/amd_math_functions.h

@@ -61,7 +61,7 @@ struct __numeric_type<_Float16>
 #define __RETURN_TYPE bool
 
 // DOT FUNCTIONS
-#if __HIP_CLANG_ONLY__
+#if defined(__clang__) && defined(__HIP__)
 __DEVICE__
 inline
 int amd_mixed_dot(short2 a, short2 b, int c, bool saturate) {