msm: krait-regulator: do not force auto mode at probe time

Auto mode should be enabled only when the PMIC is operating in single
phase. The current driver enables it at probe time - likely when there
could be multiple phases on. Do not set to Auto mode at probe time.

CRs-Fixed: 667725
Change-Id: I0213e9abb156568a0dde8e5d2c30564160027ab6
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>