dt-bindings: thermal: lmh: update maintainer address

The old email is no longer functioning.

Fixes: 17b1362d ("MAINTAINERS: Update email address")
Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://lore.kernel.org/r/20230823223622.91789-1-david@ixit.cz


Signed-off-by: Rob Herring <robh@kernel.org>