msm: clock-rpm: Have RPM handoff account for the RPM-SMD driver

The RPM-SMD driver and the correponding communication protocol
with the RPM does not currently support querying of clock rates.
Allow handoff to always succeed for RPM-SMD clocks. Previously,
the older RPM driver API stub would always return failure
causing RPM handoff to fail.

Change-Id: I357430dec06a2305cdad2af4c213a3b98965e1e1
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>