hwmon: New driver for the SMSC EMC6W201

This is a new driver for the SMSC EMC6W201 hardware monitoring device.
The device is functionally close to the EMC6D100 series, but is
register-incompatible.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Harry G McGavran Jr <w5pny@arrl.net>
Tested-by: Jeff Rickman <jrickman@myamigos.us>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>