thermal/debugfs: Print initial trip temperature and hysteresis in tze_seq_show()

The temperature and hysteresis of a trip point may change during a
mitigation episode it is involved in (it may even become invalid
altogether), so in order to avoid possible confusion related to that,
store the temperature and hysteresis of trip points at the time they
are crossed on the way up and print those values instead of their
current temperature and hysteresis.

Fixes: 7ef01f22 ("thermal/debugfs: Add thermal debugfs information for mitigation episodes")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>