ARM: dts: msm: Add regulator cooling device for SM6150

Add regulator cooling device for SM6150. These cooling devices will be
used to place minimum voltage restriction at low temperature for CX
and MX rails.

Change-Id: I20ac938c79c4bc31499afdfdf03d0e588ee28b06
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>