Merge branch 'acpica'

Merge branch 'acpica'

* acpica:
  ACPICA: Update version to 20130725.
  ACPICA: Update names for walk_namespace callbacks to clarify usage.
  ACPICA: Return error if DerefOf resolves to a null package element.
  ACPICA: Make ACPI Power Management Timer (PM Timer) optional.
  ACPICA: Fix divergences of the commit - ACPICA: Expose OSI version.
  ACPICA: Fix possible fault for methods that optionally have no return value.
  ACPICA: DeRefOf operator: Update to fully resolve FieldUnit and BufferField refs.
  ACPICA: Emit all unresolved method externals in a text block
  ACPICA: Export acpi_tb_validate_rsdp().
  ACPI: Add facility to remove all _OSI strings
  ACPI: Add facility to disable all _OSI OS vendor strings
  ACPICA: Add acpi_update_interfaces() public interface
  ACPICA: Update version to 20130626
  ACPICA: Fix compiler warnings for casting issues (only some compilers)
  ACPICA: Remove restriction of 256 maximum GPEs in any GPE block
  ACPICA: Disassembler: Expand maximum output string length to 64K
  ACPICA: TableManager: Export acpi_tb_scan_memory_for_rsdp()
  ACPICA: Update comments about behavior when _STA does not exist