hwmon: (max1619) Clamp temperature range when writing limits

hwmon: (max1619) Clamp temperature range when writing limits

Module test code reports underflows when writing sensor limits.

temp2_min: Suspected underflow: [min=-77000, read 101000, written -2147483648]
temp2_max: Suspected underflow: [min=-77000, read 101000, written -2147483648]
temp2_crit: Suspected underflow: [min=-77000, read 101000, written -2147483648]

Clamp temperature ranges when writing limits to fix the problem.
While at it, use sign_extend32() when reading temperatures to make
the code easier to understand.

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>