Merge thorpej-cfargs2.

branches: 1.7.8;
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: 1.6.2;
Rename of_match_compat_data() to of_compatible_match(). Similarly,
rename of_search_compatible() to of_compatible_lookup().

Standardize on of_compatible_match() for driver matching, and adapt
all call sites.

use fdtbus_intr_establish_xname

branches: 1.4.14;
Register shutdown handlers

branches: 1.3.2;
Stop potential misuse of vendor names and USB vendor IDs in root hub
device and string descriptors.

Firstly: Few vendors have identical PCI-SIG vendor IDs and USB-IF vendor
IDs. As such, using the PCI vendor ID as a USB vendor ID may trample
on whomever is allocated that USB vendor ID.

Secondly: The vendor of the host controller hardware implementation has
little to nothing to do with our usbroothub implementation. Thus we
should not potentially associate any problems therewith to such third
party.

This change will result in root hubs being identified by USB Vendor ID
0x0000. Root hub vendor string will now be "NetBSD" (or, specifically:
ostype). Product ID (0x0000) and product strings remain unchanged.

branches: 1.2.4; 1.2.6; 1.2.8; 1.2.10;
Remove the hack to find companion devices and just assume 1 companion if
ETTF flag is not set.

Add glue for generic ehci/ohci bindings.