Adding efa for backwards compatibility (#810)

Author: amanshanbhag

3.test_cases/megatron/nemo/slurm/env_vars.json

@@ -4,5 +4,6 @@
     "NVTE_ASYNC_AMAX_REDUCTION": "1",
     "NVTE_FUSED_ATTN": "0",
     "FI_EFA_USE_HUGE_PAGE": "0",
-    "NCCL_DEBUG": "INFO"
-}
+    "NCCL_DEBUG": "INFO",
+    "FI_PROVIDER": "efa"
+}