ARM: dts: qcom: pm8941: Add thermal zone config

Add thermal zone for the PMIC thermal sensor.

Signed-off-by: Matti Lehtimäki <matti.lehtimaki@gmail.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230529221501.43455-4-matti.lehtimaki@gmail.com