mfd: pmic: Add voltage switch test registers to PMIC core drivers

Specify the SSBI test register address for each of the voltage
switches in PMIC 8018, 8038, and 8921 core drivers.  This will
allow for future handling of over current protection (OCP) in
the pm8xxx-regulator driver.

Also define the OCP IRQs associated with each of the switches
on these PMICs.

Change-Id: Icfc51c01680e6e95b4348051c764f16cb91b4916
Signed-off-by: David Collins <collinsd@codeaurora.org>
6 files changed