ide: fix host drivers depending on ide_generic to probe for interfaces (take 2)

* Add mpc8xx_ide_probe() to mpc8xx.c and call it from probe_for_hwifs().

* Convert ide_arm, ide-cris, ide-h8300, ide-pnp, buddha, falconide, gayle,
  macide, q40ide, cmd640 and mpc8xx host drivers to use ide_device_add().

  This removes dependency on ide_generic for these drivers so update
  ide/Kconfig accordingly.

v2:
* ide_arm build fix (s/ide_device_idx/ide_device_add/)
  (Thanks to Christoph Lameter <clameter@sgi.com> for reporting the problem).

Cc: Mikael Starvik <starvik@axis.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>