dt-bindings: net: ti: k3-am654-cpsw-nuss: Add J784S4 CPSW9G support

Update bindings for TI K3 J784S4 SoC which contains 9 ports (8 external
ports) CPSW9G module and add compatible for it.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>