Add support for working around controllers that cannot do DMA in 48bit.
The workaround use PIO mode above ~137GB to allow using the disk.
Add the Acer chips with rev < 0xc4 as first candidate.
Add support for the Promise PDC4071[89] chips on the Fasttrak TX4300.
Docs kindly provided by Promise.
Apply fix for "pr82261 DMA-support on Sparc64 broken"
Use the bio field instead of the driver field as intended.
Dont set default mode to ATA_DMA_MAX on devices not capable of DMA.
Approved by: re@ (scottl)
4e9db3bd6f