ARM: dts: msm: Add regulator cooling device for SDM855

Add regulator cooling device for SDM855. These cooling devices will be
used to place minimum voltage restriction at low temperature for CX, MX
and EBI rails.

Change-Id: I3631dd9f9a708f47ab905916aaa4318e648a2ef2
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>