ACPI battery: fribble sysfs files from a resume notifier

Commit da8aeb92 re-poked the battery on resume, but Linus reports that
it broke his eee and partially reverted it in b23fffd7. Unfortunately
this also results in my x201s giving crack values until the sysfs files
are poked again. In the revert message, it was suggested that we poke it
from a PM notifier, so let's do that.

With this in place, I haven't noticed the units going nutty on my
gnome-power-manager across a dozen suspends or so...

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>