ARM: dts: rzg1: Add missing Ethernet PHY resets

Describe all Ethernet PHY reset GPIOs on RZ/G1 boards, to avoid relying
solely on boot loaders to bring PHYs out of reset.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/e20b3643b4dc5f6c2a9e19d9544495c06075d9ff.1631177442.git.geert+renesas@glider.be