thermal: core: Rename function argument related to trip crossing

Rename the 'crossed_up' function argument to 'upward', which is more
proper English and a better match for representing temperature change
direction, everywhere in the code.

No functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://patch.msgid.link/2360961.ElGaqSPkdT@rjwysocki.net


[ rjw: Rebased ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>