rocr: Switch back to legacy IPC (#1751)

Switch back to legacy IPC Implementation while we fix some race
conditions.

Co-authored-by: David Yat Sin <David.YatSin@amd.com>

Author: kentrussell

runtime/hsa-runtime/core/util/flag.h

@@ -242,7 +242,7 @@ class Flag {
     enable_mwaitx_ = (var == "1") ? true : false;
 
     var = os::GetEnvVar("HSA_ENABLE_IPC_MODE_LEGACY");
-    enable_ipc_mode_legacy_ = (var == "1") ? true : false;
+    enable_ipc_mode_legacy_ = (var == "0") ? false : true;
 
     if (os::IsEnvVarSet("HSA_PCS_MAX_DEVICE_BUFFER_SIZE")) {
       var = os::GetEnvVar("HSA_PCS_MAX_DEVICE_BUFFER_SIZE");