net: stmmac: Integrate EST with TAPRIO scheduler API

Now that we have the EST code for XGMAC and QoS we can use it with the
TAPRIO scheduler. Integrate it into the main driver and use the API to
configure the EST feature.

Signed-off-by: Jose Abreu <Jose.Abreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>