arm64: dts: qcom: sc7280: Mark PCIe controller as cache coherent

If the controller is not marked as cache coherent, then kernel will
try to ensure coherency during dma-ops and that may cause data corruption.
So, mark the PCIe node as dma-coherent as the devices on PCIe bus are
cache coherent.

Cc: stable@vger.kernel.org
Fixes: 92e0ee9f ("arm64: dts: qcom: sc7280: Add PCIe and PHY related node")
Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/1677584952-17496-1-git-send-email-quic_krichai@quicinc.com