Fix mmconf (PCIe memory mapped config space access) support in v2. It was

horribly broken and thus never used by any platform. This needs to get
straightened out so current chipsets drivers can use the full feature set.

Create wrapper functions similar to the io pci config space ones.

Signed-off-by: Stefan Reinauer <stepan@coresystems.de>
Acked-by: Myles Watson <mylesgw@gmail.com>
git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3981 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1