ENGR00274056-3 thermal: imx: binding device cooling to thermal

ENGR00274056-3 thermal: imx: binding device cooling to thermal

1. imx thermal depends on device cooling config, as only cpu
cooling is not enough for cooling down SOC;

2. binding device cooling to imx thermal driver.

3. add temperature buffer for passive trip, which means when
temperature cross passive trip, cooling devices will be triggered,
but only when temperature drop to more than the number we defined(10 C)
lower than passive trip, cooling devices will be canceled. this
is to avoid triggering/canceling cooling device back and forth when
temperature is around passive trip.

Signed-off-by: Anson Huang <b20788@freescale.com>