thermal: intel: Set THERMAL_TRIP_FLAG_RW_TEMP directly

Some Intel thermal drivers need/want the temperature of their trip
points to be set by user space via sysfs and so they pass nonzero
writable trip masks during thermal zone registration for this purpose.

It is now possible to achieve the same result by setting the
THERMAL_TRIP_FLAG_RW_TEMP trip flag directly, so modify the drivers
in question to do that instead of using a nonzero writable trips mask.

No intentional functional impact.

Note that this change is requisite for dropping the mask argument from
thermal_zone_device_register_with_trips() going forward.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>