hwmon: (w83795) Don't pre-read values we'll update later

hwmon: (w83795) Don't pre-read values we'll update later

There is no point in reading registers during initialization if we
will refresh the values in the update function later. This is only
slowing down the driver loading with no benefit, stop doing it.
This change saves 480 ms on driver load on my test system.

Signed-off-by: Jean Delvare <khali@linux-fr.org>