msm: acpuclock-9615: Vote for VDD_DIG via the new voltage corner regulator

Vote on the new voltage corner regulator (that indirectly
sets the voltage on PM8018_S1) instead of voting for a
specific voltage on S1.

Change-Id: I1c981a536a28f7e9c9e324a4b3b16226fa2a2b0c
CRs-fixed: 354458
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
Signed-off-by: David Collins <collinsd@codeaurora.org>