Expose ROCr build ID.

Adds HSA_AMD_SYSTEM_INFO_BUILD_VERSION=0x200 to hsa_system_info_t.
This returns a const char* pointing at the build string (git describe).

Change-Id: I73e6612482bf6ffc4037fd365808eb9211a650ad

runtime/hsa-runtime/core/runtime/runtime.cpp

@@ -585,6 +585,10 @@ hsa_status_t Runtime::GetSystemInfo(hsa_system_info_t attribute, void* value) {
 
       break;
     }
+    case HSA_AMD_SYSTEM_INFO_BUILD_VERSION: {
+      *(const char**)value = STRING(ROCR_BUILD_ID);
+      break;
+    }
     default:
       return HSA_STATUS_ERROR_INVALID_ARGUMENT;
   }