arm64: dts: qcom: sa8775p: mark ethernet devices as DMA-coherent

Ethernet devices are cache coherent, mark it as such in the dtsi.

Fixes: ff499a0f ("arm64: dts: qcom: sa8775p: add the first 1Gb ethernet interface")
Fixes: e952348a ("arm64: dts: qcom: sa8775p: add a node for EMAC1")
Signed-off-by: Sagar Cheluvegowda <quic_scheluve@quicinc.com>
Link: https://lore.kernel.org/r/20240514-mark_ethernet_devices_dma_coherent-v4-1-04e1198858c5@quicinc.com


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