kernel: Sync ACPICA with Intel's version 20140424.

kernel: Sync ACPICA with Intel's version 20140424.

Some highlights:

* Implemented support to skip/ignore NULL address entries in the
  RSDT/XSDT.

* Removed an extraneous error message for the case where there
  are a large number of system GPEs (> 124).

* Implemented and deployed additional configuration support for
  the public ACPICA external interfaces.

* iASL and disassembler: Add full support for the LPIT table
  (Low Power Idle Table).

* AcpiDump utility:
  1) Add option to force the use of the RSDT (over the XSDT).
  2) Improve validation of the RSDP signature (use 8 chars
     instead of 4).

* Debugger: Updated the GPE command (which simulates a GPE by
  executing the GPE code paths in ACPICA).

* Unix application OSL: Update line-editing support.

For a more detailed list, see sys/contrib/dev/acpica/changes.txt.