defconfig: Enable regulator cooling device for SDM845

Enable regulator cooling device for SDM845. Regulator cooling can place
a voltage floor mitigation on a regulator when a temperature condition
is reached.

Change-Id: I1912ebecfae871c0ea46f57fcc49d26a88ff1a7d
Signed-off-by: Ram Chandrasekar <rkumbako@codeaurora.org>