ide: remove ->hold field from ide_hwif_t (take 2)

->hold is write-only now, remove it.

v2:
* v1 missed bast-ide, palm_bk3710, ide-cs and delkin_cb host drivers.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>