thermal: intel: intel_soc_dts_iosf: Always use 2 trips

Both the existing callers of intel_soc_dts_iosf_init() pass 2 as the trip
count argument, so it can be replaced with SOC_MAX_DTS_TRIPS everywhere in
the code and the trip_count argument of that function can be dropped.

This also allows the trip_count field to be dropped from struct
intel_soc_dts_sensor_entry, as it is always equal to 2, and some
related code can be simplified.

Make changes accordingly.

No intentional functional impact.

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