This doubles the number of cooling-levels.
In addition the fan is turned on with a low speed at lower temperatures
and with a higher speed at higher temperatures.
This also attempts to reduce the likelihood of constant start-stop actions.
The change only affects the GL.iNet MT3000 and has been tested with it.
Signed-off-by: Łukasz M <lukasz1992m@gmail.com>
(cherry picked from commit 5a603c7a31)
91ef14a487