dt-bindings: thermal: correct thermal zone node name limit

dt-bindings: thermal: correct thermal zone node name limit

Linux kernel uses thermal zone node name during registering thermal
zones and has a hard-coded limit of 20 characters, including terminating
NUL byte.  The bindings expect node names to finish with '-thermal'
which is eight bytes long, thus we have only 11 characters for the reset
of the node name (thus 10 for the pattern after leading fixed character).

Reported-by: Rob Herring <robh@kernel.org>
Closes: https://lore.kernel.org/all/CAL_JsqKogbT_4DPd1n94xqeHaU_J8ve5K09WOyVsRX3jxxUW3w@mail.gmail.com/
Fixes: 1202a442a31f ("dt-bindings: thermal: Add yaml bindings for thermal zones")
Cc: stable@vger.kernel.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240702145248.47184-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>