[SCSI] advansys: More PCI cleanups

 - Remove wrappers around the PCI configuration space accessors
 - Call pci_set_master() instead of poking at config space directly
 - Move the latency setting into one function called for both narrow and
   wide boards.
 - Tidy up AdvInitGetConfig() a little.
 - Delete a few unused prototypes and definitions.

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>