ARM: dts: gemini: Remove "cooling-{min|max}-level" for gpio-fan node

The "cooling-min-level" and "cooling-max-level" properties are not
parsed by any part of the kernel currently and the max cooling state of
gpio-fan cooling device is found by referring to the
"gpio-fan,speed-map" instead.

Remove the unused properties from the gpio-fan node.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>