skylake: SPI code cleanup

Move base address into iomap.h.  Use PCI symbols instead of SPI specific
symbols.  Fix comments.

BRANCH=none
BUG=chrome-os-partner:44827
TEST=Build and run on kunimitsu

Change-Id: Id5d21603150b52fd1b71dd448105938bd6aff1a9
Signed-off-by: Lee Leahy <Leroy.P.Leahy@intel.com>
Reviewed-on: http://review.coreboot.org/11826
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
4 files changed