ARM: dts: qcom: add ethernet definitions to ipq8064

Plumb in the 4 IPQ8064 stmmac based ethernet interfaces.

Signed-off-by: Jonathan McDowell <noodles@earth.li>
Link: https://lore.kernel.org/r/723344332357b5eed957443ec4a705a080fcc2da.1589824955.git.noodles@earth.li


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>