hpt366: simplify UltraDMA filtering (take 4)

Simplify UltraDMA mode filtering in the driver:

- make use of the newly introduced 'udma_mask' field of 'ide_pci_device_t' to
  set the correct hwif->ultra_mask, modifying init_setup_hpt366() to select
  the correct mask based on the chip revision;

- replace 'max_mode' field of the 'struct hpt_info' with 'max_ultra' specifying
  the maximum UltraDMA mode allowed;

- rewrite hpt3xx_udma_filter() to differ the filters based on the 'chip_type'
  field, and only use it for HPT366 and HPT370[A] where it's really necessary.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>