net: stmmac: xgmac: Add TBS support

Adds all the necessary HW hooks to support TBS feature in XGMAC cores.

Changes from v1:
- Remove unneeded LT shift as the IP already does this.

Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>