drivers: thermal: regulator-cdev: Snapshot of regulator cooling device

Add a snapshot of regulator cooling device driver from msm-4.19 as of
'commit <f2c81ce379ec7> ("drivers: thermal: Handle min state clear
condition properly")'.

Change-Id: If6ab9e571673b01e5aea6fd80f0f4003ae724440
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>