env: Move env_init() to env.h

Move env_init() over to the new header file.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

include/env.h

@@ -21,6 +21,16 @@
  */
 int env_get_id(void);
 
+/**
+ * env_init() - Set up the pre-relocation environment
+ *
+ * This locates the environment or uses the default if nothing is available.
+ * This must be called before env_get() will work.
+ *
+ * @return 0 if OK, -ENODEV if no environment drivers are enabled
+ */
+int env_init(void);
+
 /**
  * env_get_f() - Look up the value of an environment variable (early)
  *