adding Pegasus IDE quirk for pata_via

[Alan Cox]

> Again some comments would be appreciated from anyone who has a better idea on how this controller
> works. This simple code addition came out of 2 or 3 days of discussion with the Pegasos designer
> based on his experiences with the chip and is so simple there cannot be much wrong with it
> apart from coding style and a distinct lack of testing.

Seems sane to me - as you said the x86 world relies on the BIOS for this
and in fact pretty much never uses native mode anyway.

Patch looks fine except pci_find_device is obsolete, please use
pci_get_device and refcount safe APIs.