cnss2: Add support to create device sysfs group

Currently CNSS driver creates sysfs nodes from different paths.
Add support to create device sysfs group to consolidate the paths
so that it will be easy to extend in the future.

Change-Id: I9e923288018cad558d3cd591f08f73dcf9c60219
Signed-off-by: Yue Ma <yuem@codeaurora.org>