dt-bindings: thermal: tsens: Convert over to a yaml schema

Older IP only supports the 'uplow' interrupt, but newer IP supports
'uplow' and 'critical' interrupts. Document interrupt support in the
tsens driver by converting over to a YAML schema.

Suggested-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/d519be4c7198f47c3661f7326d1a724b97dc4973.1572526427.git.amit.kucheria@linaro.org