regulator: cpr-regulator: make cpr redundant fuse checking optional

Currently, CPR redundant fuse checking for CPR ring oscillation
selection and target quotient values is mandatory.

However, some devices lack these redundant fuse bits in order to save
space. Therefore, redefine the affected device tree properties as
optional and update the cpr-regulator driver so that it can function
without them.

Change-Id: I5461fc4b173fac318986d7762bbcb15ba86a5a88
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>