hwmon: (ltc4215) Auto-convert to use SENSOR_DEVICE_ATTR_{RO, RW, WO}

Conversion was done done using the coccinelle script at
https://github.com/groeck/coccinelle-patches/raw/master/hwmon/sensor-devattr-w6.cocci



Signed-off-by: Guenter Roeck <linux@roeck-us.net>