ARM: dts: sun7i: A20-olinuxino-lime2: Fix ethernet phy-mode

Commit bbc4d71d ("net: phy: realtek: fix rtl8211e rx/tx delay
config") sets the RX/TX delay according to the phy-mode property in the
device tree. For the A20-olinuxino-lime2 board this is "rgmii", which is the
wrong setting.

Following the example of a900cac3

 ("ARM: dts: sun7i: a20: bananapro:
Fix ethernet phy-mode") the phy-mode is changed to "rgmii-id" which gets
the Ethernet working again on this board.

Signed-off-by: Bastien Roucariès <rouca@debian.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20210916081721.237137-1-rouca@debian.org