msm: clock-krait-8974: Fall back to safest PVS when table not found

If there is new hardware that uses unexpected PVS/Speed bin bits, we
should fall back to the safest PVS table instead of failing to probe.
Implement this fall back during clock-krait-8974 probe.

Change-Id: Ie2b06839cac7e5e63eb99df69f9a0aa20744c6c5
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>