powerpc: disable IDE subsystem in pq2fads_defconfig

This patch disables deprecated IDE subsystem in pq2fads_defconfig
(no IDE host drivers are selected in this config so there is no valid
reason to enable IDE subsystem itself).

Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Scott Wood <oss@buserror.net>