rockchip: dts: rk3399-evb: Change the tx/rx delay value for transmission quality

rockchip: dts: rk3399-evb: Change the tx/rx delay value for transmission quality

Give the mac controller the correct tx-delay and rx-delay value
for the rgmii mode transmission. If they are not matched, there
would be Ethernet packets lost, the net feature may not work.

Signed-off-by: David Wu <david.wu@rock-chips.com>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>