hwmon: (lm75) Per-chip configuration register initialization

There is no standard for the configuration register bits of LM75-like
chips. We shouldn't blindly clear bits setting the resolution as they
are either unused or used for something else on some of the supported
chips.

So, switch to per-chip configuration initialization. This will allow
for better tuning later, for example using more resolution bits when
available.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>