arm64: dts: qcom: sa8155p-adp: Correct ethernet/rgmii related pinmux & queues

As suggested by Bjorn, corrected the rgmii related pinmux (making
it similar to the downstream dts code).

And also alter the multi-tx and multi-rx queue constructs as found
working on the adp board with static IP addresses.

Signed-off-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>