sunxi: dts: Update RGMII phy-mode properties

Commit f11513d9 ("net: phy: realtek: Add tx/rx delay config for
8211e") made the Realtek PHY driver honour the phy-mode DT property,
to set up the proper delay scheme for the RX and TX lines. A similar
change in the kernel revealed that those properties were mostly wrong.
The kernel DTs got updated over the last few months, but we were missing
out on the U-Boot version.

Just sync in the phy-mode properties from the mainline kernel,
v5.17-rc7, to avoid the breaking DT sync that late in the cycle.

This fixes Ethernet operation on the affected boards.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Samuel Holland <samuel@sholland.org>