realtek: rtl930x: mcx3: specify RTL8224 reset GPIO

realtek: rtl930x: mcx3: specify RTL8224 reset GPIO

The nRESET pins of the RTL8224 PHY on the MCX3 are wired to GPIO6 of the
SoC, but this was never described in the devicetree.

Commit c99a30668d5f ("realtek: add RTL8224 initialization to Realtek
driver") introduced support for reinitializing RTL8224 PHYs, and commit
084da38a2e74 ("realtek: mdio: activate multiple busses") allowed the MDIO
bus provider load the devicetree properties to the bus, including reset
descriptors. With both in place, a bus level PHY reset via the hardware pin
is now correctly triggered before reinitialization.

Add the missing reset-gpios property so the PHY can be reset via the
hardware pin.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Link: https://github.com/openwrt/openwrt/pull/22966
Signed-off-by: Robert Marko <robimarko@gmail.com>