regulator: cpr-regulator: Update CPR de-aging algorithm

Configure vdd-supply to PWM mode for CPR de-aging measurements.
Also, perform multiple aging measurements and then average the
results in order to determine the final aging adjustment value.

Also, during CPR aging measurements for some power-domains it may
not be required to bypass the sensors. Handle this case by making
the sensor-bypass property optional.

CRs-Fixed: 913916
Change-Id: Ifb8447f1afe379c7108dca4e96d733dd256703e7
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>