drivers: lmh-dcvsh: Use the new cpu platform cooling device interface

Use the new CPU platform cooling device interface to register CPU
cooling devices. With the use of new interface, there will be one
cooling device per cpu frequency policy.

For CPUs with different policy but sharing same LMH, the LM driver will
aggregate the requests from both the cooling devices, before sending it
to the hardware.

Change-Id: Id629df325e402db3c5a18222685c5bf07b24b00b
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>