Use the observation that the critical and hot trip points are never
updated by the ACPI thermal driver, because the flags passed from
acpi_thermal_notify() to acpi_thermal_trips_update() do not include
ACPI_TRIPS_CRITICAL or ACPI_TRIPS_HOT, to move the initialization
of those trip points directly into acpi_thermal_get_trip_points() and
reduce the size of __acpi_thermal_trips_update().

Also make the critical and hot trip points initialization code more
straightforward and drop the flags that are not needed any more.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>