palm_bk3710: ide_register_hw() -> ide_device_add()

palm_bk3710: ide_register_hw() -> ide_device_add()

* Convert palm_bk3710 host driver to use ide_device_add() instead of
  ide_register_hw() (while at it drop doing "ide_unregister()" loop which
  tries to unregister _all_ IDE interfaces if useable ide_hwifs[] slot
  cannot be find).

  [ identical change as done to bast-ide/ide-cs/delkin_cb host drivers
    by commit 5b9df1bf3b66149030c2a2a7856e39571686f1bb ]

* Rename 'ide_ctlr_info' to 'hw' and 'index' to 'i' while at it.

Cc: Anton Salnikov <asalnikov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>