piix: backport short cables support from ata_piix.c

Backport short cables support from ata_piix.c.

This patch should allow UDMA > 2 modes on:
- Acer 5602WLMi
- Acer 3682WLMi
- Asus W5F
- Acer Aspire 2023WLMi

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