Staging: w35und: Merge mlmetxrx.c to mds.c

This patch merges mlmetxrx.c to mds.c because it's small and the functions are
only used in mto.c.

Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>