powerpc: disable IDE subsystem in pasemi_defconfig

This patch disables deprecated IDE subsystem in pasemi_defconfig
(no IDE host drivers are selected in this config so there is no valid
reason to enable IDE subsystem itself).

Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>