power_supply: Add power supply type "Charge Pump"

Introduce a new power supply type "Charge Pump" under the power_supply
class. Also, add power supply properties corresponding to power supply
type charge pump.

Change-Id: Ic2ae389601afba37a882d18d5fbb986f86fd3067
Signed-off-by: Umang Agrawal <uagrawal@codeaurora.org>
Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org>