staging: most: usb: use macro ATTRIBUTE_GROUPS

This patch makes use of the macro ATTRIBUTE_GROUPS to create the groups
instead of defining them manually.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Reported-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/1589534465-7423-7-git-send-email-christian.gromm@microchip.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>