env: Discern environment coming from external storage

Add another custom environment flag which discerns environment coming
from external storage from environment set by U-Boot itself.

Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/env/mmc.c b/env/mmc.c
index aca61b7..af7e5fb 100644
--- a/env/mmc.c
+++ b/env/mmc.c
@@ -338,7 +338,7 @@
 	read2_fail = read_env(mmc, CONFIG_ENV_SIZE, offset2, tmp_env2);
 
 	ret = env_import_redund((char *)tmp_env1, read1_fail, (char *)tmp_env2,
-				read2_fail);
+				read2_fail, H_EXTERNAL);
 
 fini:
 	fini_mmc_for_env(mmc);
@@ -380,7 +380,7 @@
 		goto fini;
 	}
 
-	ret = env_import(buf, 1);
+	ret = env_import(buf, 1, H_EXTERNAL);
 	if (!ret) {
 		ep = (env_t *)buf;
 		gd->env_addr = (ulong)&ep->data;