arm64: dts: qcom: qcs6490-rb3gen2: Add PCIe nodes

arm64: dts: qcom: qcs6490-rb3gen2: Add PCIe nodes

Enable PCIe1 controller and its corresponding PHY nodes on
qcs6490-rb3g2 platform.

SMMU v2 has limited SID's to assign dynamic SID's with the existing
logic. For now, use static iommu-map table assigning unique SID's for
each port as dynamic approach needs boarder community discussions.

PCIe switch connected to this board has 3 downstream ports and
to the one of the downstream an embedded ethernet is connected.
Assign unique SID for each downstream port and to embedded ethernet,
and also reserve a SID for the endpoints which are going to be
connected to the other two downstream ports.

As this PCIe switch is present in this platform only update iommu-map
in this platform only as other board variants might have different
PCIe topology and might need different mapping.

Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
Link: https://lore.kernel.org/r/20241024-enable_pcie-v2-1-e5a6f5da74e4@quicinc.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>