thermal: intel: intel_soc_dts_iosf: Rework critical trip setup

thermal: intel: intel_soc_dts_iosf: Rework critical trip setup

Critical trip points appear in the DTS thermal zones only after those
thermal zones have been registered via intel_soc_dts_iosf_init().
Moreover, they are "created" by changing the type of an existing trip
point from THERMAL_TRIP_PASSIVE to THERMAL_TRIP_CRITICAL via
intel_soc_dts_iosf_add_read_only_critical_trip(), the caller of which
has to be careful enough to pass at least 1 as the number of read-only
trip points to intel_soc_dts_iosf_init() beforehand.

This is questionable, because user space may have started to use the
trips at the time when intel_soc_dts_iosf_add_read_only_critical_trip()
runs and there is no synchronization between it and sys_set_trip_temp().

To address it, use the observation that nonzero number of read-only
trip points is only passed to intel_soc_dts_iosf_init() when critical
trip points are going to be used, so in fact that function may get all
of the information regarding the critical trip points upfront and it
can configure them before registering the corresponding thermal zones.

Accordingly, replace the read_only_trip_count argument of
intel_soc_dts_iosf_init() with a pair of new arguments related to
critical trip points: a bool one indicating whether or not critical
trip points are to be used at all and an int one representing the
critical trip point temperature offset relative to Tj_max.  Use these
arguments to configure the critical trip points before the registration
of the thermal zones and to compute the number of writeable trip points
in add_dts_thermal_zone().

Modify both callers of intel_soc_dts_iosf_init() to take these changes
into account and drop the intel_soc_dts_iosf_add_read_only_critical_trip()
call, that is not necessary any more, from intel_soc_thermal_init(),
which also allows it to return success right after requesting the IRQ.

Finally, drop intel_soc_dts_iosf_add_read_only_critical_trip()
altogether, because it does not have any more users.

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