thermal: imx: dynamic passive and SoC specific critical trip points

Set passive and critical trip point values depending on the maximum die
temperature stored in the OCOTP fuses. This allows higher trip points
for industrial and automotive rated i.MX6 SoCs.
Also allow to configure the passive trip point from userspace.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>