[DCU] fix 2.5 compile issues

transformer_engine/common/util/multi_stream.cpp

@@ -18,6 +18,21 @@
 #include "cuda_runtime.h"
 #include "logging.h"
 
+static inline int getIntEnv(const char *name, int defval, int minval)
+{
+  int val = defval;
+  const char* env = std::getenv(name);
+  if (env != nullptr && env[0] != '\0')
+  {
+     val = atoi(env);
+     if (val < minval)
+     {
+        val = minval;
+     }
+  }
+  return val;
+}
+
 namespace transformer_engine::detail {
 
 cudaStream_t get_compute_stream(int idx) {