regulator: cpr-regulator: set pvs_version to 0 if PVS fuse not present

Some devices do not have PVS version fuse bits. In such cases the
qcom,pvs-version-fuse-sel property cannot be specified. Initialize
pvs_version to 0 in the case that qcom,pvs-version-fuse-sel is not
present. This allows virtual corners to be used when there are no PVS
version fuse bits.

Change-Id: I835cc12c942a464bfda354fe53b9361ff352cf31
Signed-off-by: Fenglin Wu <fenglinw@codeaurora.org>