ide: Force VIA IDE legacy interrupts for AmigaOne boards

The AmigaOne uses the onboard VIA IDE controller in legacy mode (like the
Pegasos).

Signed-off-by: Gerhard Pircher <gerhard_pircher@gmx.net>
Cc: "Grant Likely" <grant.likely@secretlab.ca>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>