driver: net: ti: cpsw: update to use SPDX identifier

Update to use SPDX license identifier.

Reviewed-by: Tom Rini <trini@konsulko.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
1 file changed