Block ROCm 4.1+ running against 4.0 and prior kfd.

Sramecc is misreported in kfd 4.0 and prior.  To prevent possible
corruption due to d16 instructions, deny use of gfx906 with older
kfds and correct misreport for gfx908.  Denial of gfx906 may be
overridden by setting HSA_IGNORE_SRAMECC_MISREPORT=1.

Change-Id: I7d5c3a716fad01c348f8b88cd508cedbf914c989

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

@@ -127,6 +127,9 @@ class Flag {
 
     var = os::GetEnvVar("HSA_FORCE_SDMA_SIZE");
     force_sdma_size_ = var.empty() ? 1024 * 1024 : atoi(var.c_str());
+
+    var = os::GetEnvVar("HSA_IGNORE_SRAMECC_MISREPORT");
+    check_sramecc_validity_ = (var == "1") ? false : true;
   }
 
   bool check_flat_scratch() const { return check_flat_scratch_; }
@@ -173,6 +176,8 @@ class Flag {
 
   size_t force_sdma_size() const { return force_sdma_size_; }
 
+  bool check_sramecc_validity() const { return check_sramecc_validity_; }
+
  private:
   bool check_flat_scratch_;
   bool enable_vm_fault_message_;
@@ -189,6 +194,7 @@ class Flag {
   bool no_scratch_thread_limit_;
   bool disable_image_;
   bool loader_enable_mmap_uri_;
+  bool check_sramecc_validity_;
 
   SDMA_OVERRIDE enable_sdma_;