hwmon: (ibmpowernv) add a helper routine create_hwmon_attr
hwmon: (ibmpowernv) add a helper routine create_hwmon_attr

This should shorten a bit the code necessary to create a hmwon attribute.

Signed-off-by: Cédric Le Goater <2d8cace2254d4e43578d21933db015d84bcc468a@fr.ibm.com>
Signed-off-by: Guenter Roeck <ba324ca7b1c77fc20bb970d5aff6eea9377918a5@roeck-us.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs