hwmon: lochnagar: Remove the unneeded include <linux/i2c.h>

This driver does not use i2c, so there is no point in including
<linux/i2c.h>

Remove it.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/df555e724d1b52bd9958c0bd729a774dfe0cf150.1682237387.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Guenter Roeck <linux@roeck-us.net>