hwmon: (lm90) Don't override interrupt trigger type

The lm90 driver sets interrupt trigger type to level-low. This type is
not suitable for sensors like NCT1008 that don't deassert interrupt line
until temperature is back to normal, resulting in interrupt storm. The
appropriate trigger type should come from OF device description and
currently it's overridden by the driver's trigger type. Don't specify
the trigger type in the driver code, letting interrupt core to use the
device-specific trigger type.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>