ide: move create_proc_ide_drives() call to ide_device_add_all()

* Un-static create_proc_ide_drives() and call it from ide_device_add_all().

While at it:
* Rename create_proc_ide_drives() to ide_proc_port_register_devices().

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