thermal: add temperature sensor support for tango SoC

The Tango thermal driver provides support for the primitive temperature
sensor embedded in Tango chips since the SMP8758.

This sensor only generates a 1-bit signal to indicate whether the die
temperature exceeds a programmable threshold.

Signed-off-by: Marc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>