BATTERY: Add missing get_property() of some property

BATTERY: Add missing get_property() of some property

The property of power should be implemented both get_property() and
set_property() but some property has only set_property() and it causes
some problem on tizen_3.0 platform like belows.

[   15.804351]  [3:systemd-journal:  188] power_supply sec-charger: driver failed to report `voltage_max' property: -22
[   27.924804]  [3:systemd-journal:  188] power_supply sec-fuelgauge: driver failed to report `status' property: -22
[   28.080047]  [3:systemd-journal:  179] power_supply sec-fuelgauge: driver failed to report `charge_full' property: -22
[   20.704162]  [0:systemd-journal:  180] power_supply sec-fuelgauge: driver failed to report `present' property: -22
[   19.580261]  [1:systemd-journal:  181] power_supply sec-fuelgauge: driver failed to report `energy_now' property: -22
[   20.989288]  [2:systemd-journal:  167] power_supply sec-fuelgauge: driver failed to report `temp' property: -22
[   20.832183]  [2:systemd-journal:  177] power_supply sec-fuelgauge: driver failed to report `temp_ambient' property: -22

This is workaround so driver should implement get_property() exactly
later.

Change-Id: I9d9650b748bdb73ae3149f0c4709908d0c0bb962
Signed-off-by: Min Kang <min1023.kang@samsung.com>
Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>