A previous version of this patch had a config for THERMAL_POWER_ACTOR
but it was dropped.  Remove the select as it is not doing anything.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Reported-by: NValentin Rothberg <valentinrothberg@gmail.com>
Signed-off-by: NJavi Merino <javi.merino@arm.com>
Signed-off-by: NEduardo Valentin <edubezval@gmail.com>