Thermal: imx: add i.mx6sx thermal support

i.MX6SX has some new features of thermal interrupt function,
there are LOW, HIGH and PANIC irq for thermal sensor, so add
platform data to separate different thermal version;

The reset value of LOW ALARM is 0 which means the highest
temp, so the LOW ALARM will be triggered once irq is enabled,
so we need to correct it before enabling thermal irq;

Enable PANIC ALARM as critical trip point, it will trigger
system reset via SRC module once PANIC IRQ is triggered, it
is pure hardware function, so use it instead of software
reset by cooling device.

Signed-off-by: Anson Huang <b20788@freescale.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>