hwmon: (it87) Replace macro defining tempX_type sensors with direct definitions

The macro name show_sensor_offset is confusing since it related to the sensor
type, not an offset - even more so when we introduce offset attributes later on.
Replace it with direct definitions, and replace the show_sensor/set_sensor
function names with show_temp_type/set_temp_type. This also resolves a
checkpatch error.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>