xhci: Always do 32-bit accesses for platform (ACPI) XHCI devices.

The XHCI IP found in the CIX CD8180 throws an serror for any access that
is not 32-bit aligned. Let's add an XHCI_32BIT_ACCESS flag and set it
unconditionally for platform devices as there are only a handful of non-
32-bit accesses at init time.

acpi: xhci: Add support for generic USB role switching device nodes.

URS nodes have a child node that contains the interrupt resource for the
XHCI. Match the URS nodes and add support for obtaining the interrupt
from this child node.

branches: 1.13.12;
Merge thorpej-cfargs2.

branches: 1.12.8;
Merge thorpej-cfargs branch:

Simplify and make extensible the config_search() / config_found() /
config_attach() interfaces: rather than having different variants for
which arguments you want pass along, just have a single call that
takes a variadic list of tag-value arguments.

Adjust all call sites:
- Simplify wherever possible; don't pass along arguments that aren't
actually needed.
- Don't be explicit about what interface attribute is attaching if
the device only has one. (More simplification.)
- Add a config_probe() function to be used in indirect configuiration
situations, making is visibly easier to see when indirect config is
in play, and allowing for future change in semantics. (As of now,
this is just a wrapper around config_match(), but that is an
implementation detail.)

Remove unnecessary or redundant interface attributes where they're not
needed.

There are currently 5 "cfargs" defined:
- CFARG_SUBMATCH (submatch function for direct config)
- CFARG_SEARCH (search function for indirect config)
- CFARG_IATTR (interface attribte)
- CFARG_LOCATORS (locators array)
- CFARG_DEVHANDLE (devhandle_t - wraps OFW, ACPI, etc. handles)

...and a sentinel value CFARG_EOL.

Add some extra sanity checking to ensure that interface attributes
aren't ambiguous.

Use CFARG_DEVHANDLE in MI FDT, OFW, and ACPI code, and macppc and shark
ports to associate those device handles with device_t instance. This
will trickle trough to more places over time (need back-end for pre-OFW
Sun OBP; any others?).

branches: 1.11.2;
Use acpi_compatible_match().

Fix 32-bit build.

branches: 1.9.2;
Report HW DMA capability and if the DMA tag limits it.

Fix DMA size reporting. Previously it could report 64bit DMA when the tag
wasn't available (and it fell back to 32bit tag)

Match HID 808622B7 (DesignWare USB3)

Choose between dmat and dmat64, instead of relying on subregion of the 32-bit tag

branches: 1.5.4;
Use bus_dmatag_subregion to get a 32-bit tag

Conditionally use a 32- or 64-bit DMA tag based on HCCPARAMS

branches: 1.3.4;
Fix cut & paste error in comment

branches: 1.2.2;
Use acpi_intr_establish

Add xhci at acpi glue