sh: pci: Consolidate the remaining common bits.

This moves the remaining common bits in to pci-lib. Thereby reducing
pci.c/pci-new.c to simple bus fixups and controller registration.

As more platforms are moved over, the old code will disappear completely
and the pci-new bits will be rolled in to pci-lib, eventually replacing
pci.c completely.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>