Staging: sxg: slicoss: Specify the license for Sahara SXG and Slicoss drivers

Specify a license for the Alacritech Sahara (10Gbe) and SLICOSS (1GBE)
firmware files.

Signed-off-by: Christopher Harrer <charrer@alacritech.com>
Signed-off-by: Mithlesh Thukral <mithlesh@linsyssoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>