ide: remove obsoleted "idex=noprobe" kernel parameter (take 2)

* Remove obsoleted "idex=noprobe" kernel parameter.

* Remove no longer needed hwif->noprobe quirk from ide_hwif_configure()
  and hwif->noprobe checking from cmd640.c.

v2:
* "ide?=noprobe" -> "ide?=ata66" in Documentation/kernel-parameters.txt.

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