powerpc/pci: Support per-aperture memory offset

The PCI core supports an offset per aperture nowadays but our arch
code still has a single offset per host bridge representing the
difference betwen CPU memory addresses and PCI MMIO addresses.

This is a problem as new machines and hypervisor versions are
coming out where the 64-bit windows will have a different offset
(basically mapped 1:1) from the 32-bit windows.

This fixes it by using separate offsets. In the long run, we probably
want to get rid of that intermediary struct pci_controller and have
those directly stored into the pci_host_bridge as they are parsed
but this will be a more invasive change.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c
index e37c215..432459c 100644
--- a/arch/powerpc/kernel/pci_32.c
+++ b/arch/powerpc/kernel/pci_32.c
@@ -295,7 +295,7 @@
 	case IOBASE_BRIDGE_NUMBER:
 		return (long)hose->first_busno;
 	case IOBASE_MEMORY:
-		return (long)hose->pci_mem_offset;
+		return (long)hose->mem_offset[0];
 	case IOBASE_IO:
 		return (long)hose->io_base_phys;
 	case IOBASE_ISA_IO: