env: Fix env_load_location

Commit 7d714a24d7 ("env: Support multiple environments") added
static variable env_load_location. When saving environmental
variables, this variable is presumed to have the value set before.
In case the value was set before relocation and U-Boot runs from a
NOR flash, this variable wasn't writable. This causes failure when
saving the environment. To save this location, global data must be
used instead.

Signed-off-by: York Sun <york.sun@nxp.com>
CC: Maxime Ripard <maxime.ripard@free-electrons.com>

include/environment.h

@@ -188,6 +188,7 @@ enum env_valid {
 };
 
 enum env_location {
+	ENVL_UNKNOWN,
 	ENVL_EEPROM,
 	ENVL_EXT4,
 	ENVL_FAT,
@@ -202,7 +203,6 @@ enum env_location {
 	ENVL_NOWHERE,
 
 	ENVL_COUNT,
-	ENVL_UNKNOWN,
 };
 
 /* value for the various operations we want to perform on the env */