sysfs.h: add ATTRIBUTE_GROUPS() macro

commit f2f37f58b1b933b06d6d84e80a31a1b500fb0db2 upstream.

To make it easier for driver subsystems to work with attribute groups,
create the ATTRIBUTE_GROUPS macro to remove some of the repetitive
typing for the most common use for attribute groups.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --cc include/linux/sysfs.h
Simple merge