arm64: dts: qcom: ipq6018: Add mdio bus description

The IPQ60xx has the same MDIO bug block as IPQ4019. Add IO range and
clock resources description.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Baruch Siach <baruch.siach@siklu.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/ef01a79ccc6ef86dc3a10d0fa3331794d49e9859.1646031524.git.baruch@tkos.co.il