drivers: lmh_dcvs: Add support to selectively register cooling devices

CPU cooling device register and handling max and min limit
functionalities are moved to cpu clock driver and cpu vdd min voltage
cooling device driver respectively. Add support to selectively
register cooling devices for LMH DCVSh driver so that other LMH DCVSh
features can be enabled without cooling device register.

Change-Id: I9e346c2410ff34c5b1dc9d0fdc19970a403007cc
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>