MLK-14291 thermal: imx: fix setting passive trip temp

MLK-14291 thermal: imx: fix setting passive trip temp

When setting passive temperature trip point, it is not
allowed to set a higher value than the default.

Currently the driver compares the new temperature to set
with a constant (0). This comparison wil always be true
(temp to set higher than 0) and the driver will return
-EINVAL. This is a leftover from rebasing the commit fc4fcd689419
("MLK-11705 thermal: imx: make the critical trip temp changable for test").

Fix the comparison by using the actual default passive
temperature value instead of the wrong constant.

Signed-off-by: Irina Tirdea <irina.tirdea@nxp.com>