now that APM_BATT_CHARGING is also set in acpi and on some m1 devices

now that APM_BATT_CHARGING is also set in acpi and on some m1 devices
enable support for displaying an estimate recharge time in apm(d)

e.g:
Battery state: charging, 95% remaining, 11 minutes recharge time estimate
Battery state: charging, 97% remaining, 8 minutes recharge time estimate
Battery state: charging, 98% remaining, 6 minutes recharge time estimate
Battery state: charging, 99% remaining, 3 minutes recharge time estimate
Battery state: charging, 99% remaining, 1 minutes recharge time estimate
Battery state: charging, 99% remaining, 0 minutes recharge time estimate

ok jca@