env: Move envmatch() to env.h

Move envmatch() over to the new header file. Also rename it to env_match()
to better line up with other functions.

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

include/env.h

@@ -39,6 +39,17 @@ int env_init(void);
  */
 void env_relocate(void);
 
+/**
+ * env_match() - Match a name / name=value pair
+ *
+ * This is used prior to relocation for finding envrionment variables
+ *
+ * @name: A simple 'name', or a 'name=value' pair.
+ * @index: The environment index for a 'name2=value2' pair.
+ * @return index for the value if the names match, else -1.
+ */
+int env_match(unsigned char *name, int index);
+
 /**
  * env_get_f() - Look up the value of an environment variable (early)
  *