hwmon: (tmp421) really disable channels

hwmon: (tmp421) really disable channels

Recent patch added possibility to disable selected channels. That would
only make sure that the ENODATA is returned for those channels but would
not configure the actual hardware.

With this patch, the config register is written to make sure the
channels are disabled also at hardware level.

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Link: https://lore.kernel.org/r/d451cacdf21bf8eff38a47c055aad8c0c6e8755a.1634206677.git.krzysztof.adamski@nokia.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>