env: common: accept flags on reset to default env

The function set_default_env() sets the hashtable flags for import_r().
Formally set_default_env() doesn't accept flags from its callers. In
practice the caller can (un)set the H_INTERACTIVE flag, but it has to be
done using the first character of the function's string argument. Other
flags like H_FORCE can't be set by the caller.

Change the function to accept flags argument. The benefits are:
1. The caller will have to explicitly set the H_INTERACTIVE flag,
   instead of un-setting it using a special char in a string.
2. Add the ability to propagate flags from the caller to himport(),
   especially the H_FORCE flag from do_env_default() in nvedit.c that
   currently gets ignored for "env default -a -f" commands.
3. Flags and messages will not be coupled together. A caller will be
   able to set flags without passing a string and vice versa.

Please note:
The propagation of H_FORCE from do_env_default() does not introduce any
functional changes, because currently himport_r() is set to destroy the
old environment regardless if H_FORCE flag is set or not. More changes
are needed to utilize the propagation of H_FORCE.

Signed-off-by: Yaniv Levinsky <yaniv.levinsky@compulab.co.il>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
diff --git a/common/board_r.c b/common/board_r.c
index e9f827a..64f2574 100644
--- a/common/board_r.c
+++ b/common/board_r.c
@@ -454,7 +454,7 @@
 	if (should_load_env())
 		env_relocate();
 	else
-		set_default_env(NULL);
+		set_default_env(NULL, 0);
 #ifdef CONFIG_OF_CONTROL
 	env_set_addr("fdtcontroladdr", gd->fdt_blob);
 #endif
diff --git a/common/spl/spl_dfu.c b/common/spl/spl_dfu.c
index b8e3a6c..01178f6 100644
--- a/common/spl/spl_dfu.c
+++ b/common/spl/spl_dfu.c
@@ -38,7 +38,7 @@
 	int ret;
 
 	/* set default environment */
-	set_default_env(0);
+	set_default_env(NULL, 0);
 	str_env = env_get(dfu_alt_info);
 	if (!str_env) {
 		pr_err("\"dfu_alt_info\" env variable not defined!\n");