thermal: qoriq: remove useless call for of_thermal_get_trip_points()

Building this driver with W=1 reports:
  warning: variable 'trip' set but not used [-Wunused-but-set-variable]

The call for of_thermal_get_trip_points() is useless.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>