hwmon: (lm75) Add STLM75 support

The STLM75 is a high-precision digital CMOS temperature sensor
IC with a sigma-delta temperature-to-digital converter.

The configuration register mapping is similar to existing lm75
but the sample rate is 150ms(max).

Tested on real hardware and verified temperature readings are correct.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>