ide: move ide_arm_init() call from init_ide_data() to ide_init()

* Remove ide_init_port_data() call from ide_arm_init() and move
  ide_arm_init() call from init_ide_data() to ide_init().

This patch is a preparation for the future changes (and as a side-effect
makes obsolete "idex=io[,ctl[,irq]]" kernel parameters work for ide_arm).

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>