arm64: dts: qcom: sc8280xp: Add ethernet nodes

This platform has 2 MACs integrated in it, go ahead and describe them.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Tested-by: Brian Masney <bmasney@redhat.com>
Signed-off-by: Andrew Halaney <ahalaney@redhat.com>
Reviewed-by: Brian Masney <bmasney@redhat.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230501205105.2518373-2-ahalaney@redhat.com