ACPI battery: support percentage battery remaining capacity

ACPI battery: support percentage battery remaining capacity

commit 557d58687dcdee6bc00c1a8f1fd4e0eac8fefce9 upstream.

According to the ACPI spec, some kinds of primary battery can
report percentage battery remaining capacity directly to OS.

In this case, it reports the LastFullChargedCapacity == 100,
BatteryPresentRate = 0xFFFFFFFF, and BatteryRemaingCapacity a
percentage value, which actually means RemainingBatteryPercentage.

Now we found some battery follows this rule even if it's a rechargeable.
https://bugzilla.kernel.org/show_bug.cgi?id=15979

Handle these batteries correctly in ACPI battery driver
so that they won't break userspace.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Tested-by: Sitsofe Wheeler <sitsofe@yahoo.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>