arm64: dts: imx8dxl-evk: Fix eqos phy reset gpio

arm64: dts: imx8dxl-evk: Fix eqos phy reset gpio

The deprecated property is named snps,reset-gpio, but this devicetree
used snps,reset-gpios instead which results in the reset not being used
and the following make dtbs_check error:

    ./arch/arm64/boot/dts/freescale/imx8dxl-evk.dtb: ethernet@5b050000: 'snps,reset-gpio' is a dependency of 'snps,reset-delays-us'
        From schema: ./Documentation/devicetree/bindings/net/snps,dwmac.yaml

Use the preferred method of defining the reset gpio in the phy node
itself. Note that this drops the 10 us pre-delay, but prior this wasn't
used at all and a pre-delay doesn't make much sense in this context so
it should be fine.

Fixes: 8dd495d12374 ("arm64: dts: freescale: add support for i.MX8DXL EVK board")
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>