arm64: dts: meson: odroidc2: readd PHY reset properties

The sync of the device tree and dt-bindings from Linux v5.6-rc2
11a48a5a18c6 ("Linux 5.6-rc2") causes Ethernet to break on some
ODROID-C2. The PHY seems to need proper reset timing to be functional
in U-Boot and Linux afterwards. Readd the old PHY reset bindings for
dwmac until we support the new bindings in the PHY node.

Fixes: dd5f2351 ("arm64: dts: meson: sync dt and bindings from v5.6-rc2")
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>