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>