thermal: intel: intel_soc_dts_iosf: Add helper for resetting trip points

Because trip points are reset for each sensor in two places in the
same way, add a helper function for that to reduce code duplication
a bit.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>