Import portions of the PowerPC OF PCI implementation into new file
"ofwpci.c", common for other platforms. The files ofw_pci.c and ofw_pci.h
from sys/powerpc/ofw no longer exist. All required declarations are moved
to sys/dev/ofw/ofwpci.h. This creates a new ofw_pci_write_ivar() function
and modifies some others methods. Most functions contain existing ppc
implementations in the majority unchanged. Now there is no need to have
multiple identical copies of methods for various architectures.
Requested by: jhibbits
Reviewed by: jhibbits, marius
Submitted by: Marcin Mazurek <mma@semihalf.com>
Obtained from: Semihalf
Sponsored by: Annapurna Labs
Differential Revision: https://reviews.freebsd.org/D4879
c43a86743c