trivial: mtd: add __init/__exit macros to init/exitfunctions

Trivial patch which adds the __init and __exit macros to the module_init /
module_exit functions to the following modules from drivers/mtd/
 devices/m25p80.c
 devices/slram.c
 linux version 2.6.30
 ftl.c
 nand/cafe_nand.c
 nand/cmx270_nand.c

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>