pci root complex: support for tile architecture

This change enables PCI root complex support for TILEPro.  Unlike
TILE-Gx, TILEPro has no support for memory-mapped I/O, so the PCI
support consists of hypervisor upcalls for PIO, DMA, etc.  However,
the performance is fine for the devices we have tested with so far
(1Gb Ethernet, SATA, etc.).

The <asm/io.h> header was tweaked to be a little bit more aggressive
about disabling attempts to map/unmap IO port space.  The hacky
<asm/pci-bridge.h> header was rolled into the <asm/pci.h> header
and the result was simplified.  Both of the latter two headers were
preliminary versions not meant for release before now - oh well.

There is one quirk for our TILEmpower platform, which accidentally
negotiates up to 5GT and needs to be kicked down to 2.5GT.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index f01e344..98e6fdf 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -49,6 +49,7 @@
 obj-$(CONFIG_X86_VISWS) += setup-irq.o
 obj-$(CONFIG_MN10300) += setup-bus.o
 obj-$(CONFIG_MICROBLAZE) += setup-bus.o
+obj-$(CONFIG_TILE) += setup-bus.o setup-irq.o
 
 #
 # ACPI Related PCI FW Functions