[ARM] 3860/1: Versatile PCI config byte accesses

The ARM Versatile board PCI config space read routines are broken for byte
accesses.  The access uses a byte read, so masking the bottom two bits of the
address is wrong.

I guess this is a cut/paste error from the the halfword code which uses
aligned word access+shift+mask.

Signed-off-by: Paul Brook <paul@codesourcery.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>