thermal: rcar_gen3_thermal: Remove temperature bound

The hardware manual states that the operation of the sensor is not
guaranteed with temperatures above 125°C, not that the readings are
invalid. Remove the bound check and try to deliver temperature readings
even if we are outside the guaranteed operation range.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200117160554.3812787-3-niklas.soderlund+renesas@ragnatech.se