ACPI: Bug compatibility for Windows on the ACPI reboot vector

Windows ignores the bit_offset and bit_width, despite the spec requiring
that they be validated. Drop the checks so that we match this behaviour.
Windows also goes straight for the keyboard controller if the ACPI reboot
fails, so we shouldn't sleep if we're still alive.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>