thermal: power_allocator: do not use devm* interfaces

The code in question is called outside of standard driver
probe()/remove() callbacks and thus will not benefit from use of devm*
infrastructure.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
(cherry picked from commit cf736ea6f902c26e03895dc7f5ccbc55cdc68e6e)
Signed-off-by: Kevin Hilman <khilman@linaro.org>