hwmon: (ibmaem) constify aem_rw_sensor_template and aem_ro_sensor_template structures

The aem_rw_sensor_template and aem_ro_sensor_template structures are never
modified, so declare them as const.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>