pci: Add PCI device infrastructure

Add generic PCI packages:

o HW.PCI containing basic definitions for PCI devices and
  configuration space headers,
o HW.PCI.MMConf that provides access to memory mapped confi-
  guration space of a PCI device, and
o HW.PCI.Dev adding a method to map resources of a PCI device.

Change-Id: I266ea35e273ff49fdb3176d617bb0b4ab1f13f93
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/20258
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
8 files changed