thermal: small style cleanup in mtk_thermal

Remove all checkpatch.pl --strict errors, checks, and warnings.

Cc: Zhang Rui <rui.zhang@intel.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mediatek@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>