dt-bindings: Add snapshot of thermal devicetree bindings

This is a snapshot of thermal devicetree bindings from devicetree-4.19
to devicetree as of 'commit <6165320c09573041178621aa7afe812b237cd388>
(dt-bindings: Add snapshot of CX Ipeak cooling device devicetree
binding)'.

Change-Id: I0fad7df5bcdb5881f61435e7875558cbd259c88a