Prior to this patch, if use_for_apm unspecified, apm_power able
to choice batteries according to their charge only.
This patch adds ability to choice batteries according to their charge,
energy, use_for_apm flag, and fallback to any battery if it failed to
decide.
Patch is mandatory to report Apple PMU batteries through legacy
/proc/apm interface using power supply class.
Signed-off-by: Anton Vorontsov <cbou@mail.ru>
Prior to this patch, apm_power was unable to report "to empty"/"to full"
time for batteries that hardware-report these values, such as
Apple PMU batteries.
Signed-off-by: Anton Vorontsov <cbou@mail.ru>