[clang][openmp] - Ensure HIP_PLATFORM is set for hip_host_overlay

Fix __has_include check to look in hip directory.
If an OpenMP program is using the HIP API (like hipMalloc),
then ensure HIP_PLATFORM_* is set. This also avoids problems
with OpenMP programs that do not use the HIP API as the header
will not be used.

Change-Id: Iac43fbef395f8ab91b9ae9744daed000d994d106

Author: estewart08

clang/lib/Headers/openmp_wrappers/hip_host_overlay.h

@@ -18,8 +18,8 @@
 // arg is set to 0 to prevent dual setting of the HSA coarse-grain attribute.
 // Only the OpenMP runtime table tracking coarse-grain memory is updated.
 
-#if defined(_OPENMP) && __has_include(<hip_runtime_api.h>)
-#include <hip_runtime_api.h>
+#if defined(_OPENMP) && __has_include(<hip/hip_runtime_api.h>) && (defined(__HIP_PLATFORM_AMD__) || defined(__HIP_PLATFORM_NVIDIA__))
+#include <hip/hip_runtime_api.h>
 #include <omp.h>
 
 // Define Overlays for HIP host functions