power: pm8921-charger: vote D0 when running kickstart

There is a small window when the PMIC could lock up while
running the kickstart routine. If PMIC sleeps right while
kickstart is run, it causes a short sleep which is known
to cause PMIC locksup.

To prevent these, specifically vote for D0 clock while
running kickstart which guarantees that the PMIC will not
sleep.

Change-Id: I9ea27ef73098d0ec5e8391352ee005d8a78daa9a
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>