board: toradex: move RGMII delays to PHY side

The RGMII link delays can be set on either MAC or PHY side. Set the
rgmii-id PHY mode for FEC and remove FEC_ENET_ENABLE_.XC_DELAY
setting, so that these definitions aren't used anymore throughout
the U-Boot.

Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
4 files changed