ACPI: add support for Smart Battery

Most batteries today are ACPI "Control Method" batteries,
but some models ship with the older "Smart Battery"
that requires this code.

Rich Townsend and Bruno Ducrot were the original authors.
Vladimir Lebedev updated to run on latest kernel.

http://bugzilla.kernel.org/show_bug.cgi?id=3734



Signed-off-by: Len Brown <len.brown@intel.com>