Add a PCI resource manager and use it on Arm ACPI platforms.

The Arm ACPI code relied on PCI_NETBSD_CONFIGURE to configure devices that
were not enabled by system firmware. This is not safe to do unless the
firmware explicitly permits it using a device specific method defined in
the PCI firmware spec.

Introduce a new PCI resource manager that discovers what has already been
configured by firmware and allocates from the remaining space. This will
ensure that devices setup by firmware are untouched and only will program
BARs of devices that are not enabled at boot time.

The current implementation assumes that the parent PCI-PCI bridge's
are already configured. A worthwhile improvement in the future would be
to support programming windows for bridges that are not fully configured.

expose acpi_pcidev_pciroot_bus

Add support for Arm N1 SDP PCIe host controller.

The N1 SDP has a few bugs that we need to work around:
- PCIe root port config space lives in a non-standard location.
- Access to PCIe config space of devices that do not exist results in
an sync SError. Firmware creates a "known devices" table at a fixed
physical address that we use to filter PCI conf access to only known
devices.

This change splits the Arm ACPI PCI quirks into separate files for each
host controller, and allows per-segment quirks to be applied.

These changes exposed some bugs in the MI ACPI layer related to
multi-segment support. The MI ACPI PCI code was using a shared PCI
chipset tag to access devices, and these accesses can happen before our
PCI host bridge drivers are attached! The global chipset tag is now gone,
and an MD callback can provide a custom tag on a per-segment basis.

branches: 1.10.6;
Add a function to report whether the operating system may ignore the boot
configuration of PCI resources for a given bus.

Add a function to find a PCI root bridge by segment and bus number.

branches: 1.8.58; 1.8.60;
acpi_pcidev_find_dev(): take struct acpi_devnode as a parameter.

Move the function that finds a device_t for the corresponding ACPI device
node from ACPIVERBOSE to the ACPI PCI code.

Simplify acpi_pcidev_find(): directly return a pointer to the device node.

Some pretty printing for ACPIVERBOSE.

From Gregoire Sutre: rework the ACPI PCI support. This makes ACPI to
correctly pick PCI segment groups, PCI bus numbers, PCI root bridges,
PCI-to-PCI bridges, and PCI devices, among other things. In short: it is
more robust than the old code or anything in sys/arch/x86/x86/mpacpi.c.

ok cegger@, jmcneill@

branches: 1.3.2; 1.3.4;
Protect all header files against multiple inclusions.

branches: 1.2.2;
Fix NetBSD keyword expansion.

Enumerate ACPI PCI devices. Allows to link PCI with ACPI devices.
Patch presented on tech-kern@
http://mail-index.netbsd.org/tech-kern/2009/11/28/msg006552.html

'nice work' Jukka Ruohonen