hwmon: (tmp108) Use maple tree register cache

hwmon: (tmp108) Use maple tree register cache

The tmp108 is only capable of performing single register read and write
operations which means it gains no advantage from using a rbtree register
cache, convert it to using the more modern maple tree register cache
instead. This should be more efficient.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230609-hwmon-maple-v1-4-8edacce86b28@kernel.org
Signed-off-by: Guenter Roeck <linux@roeck-us.net>