rtase: Add ndo_setup_tc support for CBS offload in traffic control setup

Add support for ndo_setup_tc to enable CBS offload functionality as
part of traffic control configuration for network devices, where CBS
is applied from the CPU to the switch. More specifically, CBS is
applied at the GMAC in the topmost architecture diagram.

Signed-off-by: Justin Lai <justinlai0215@realtek.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250416115757.28156-1-justinlai0215@realtek.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>