MIPS: Kill CONFIG_MTD_PARTITIONS

This patch removes CONFIG_MTD_PARTITIONS in config files for MIPS.
 Because CONFIG_MTD_PARTITIONS was removed by commit 6a8a98b2.

Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6162/


Signed-off-by: Eunbong Song <eunb.song@samsung.com>