dt-bindings: net: fec: Add imx8dxl description

The imx8dl FEC has the same programming model as the one on the imx8qxp.

Add the imx8dl compatible string.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230926111017.320409-1-festevam@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>