powerpc/83xx: disable IDE subsystem in mpc834x_itx_defconfig

This patch disables deprecated IDE subsystem in mpc834x_itx_defconfig
(no IDE host drivers are selected in this config so there is no valid
reason to enable IDE subsystem itself).

Cc: Scott Wood <oss@buserror.net>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NScott Wood <oss@buserror.net>

arch/powerpc/configs/83xx/mpc834x_itx_defconfig

@@ -35,7 +35,6 @@ CONFIG_MTD_PHYSMAP=y
 CONFIG_BLK_DEV_LOOP=y
 CONFIG_BLK_DEV_RAM=y
 CONFIG_BLK_DEV_RAM_SIZE=32768
-CONFIG_IDE=y
 CONFIG_BLK_DEV_SD=y
 CONFIG_CHR_DEV_SG=y
 CONFIG_SCSI_SPI_ATTRS=y