dt-bindings: PCI: eswin: Add ESWIN PCIe Root Complex

dt-bindings: PCI: eswin: Add ESWIN PCIe Root Complex

Add Device Tree binding documentation for the ESWIN PCIe Root Complex. The
Root Complex is based on Synopsys Designware PCIe IP.

Signed-off-by: Yu Ning <ningyu@eswincomputing.com>
Signed-off-by: Yanghui Ou <ouyanghui@eswincomputing.com>
Signed-off-by: Senchuan Zhang <zhangsenchuan@eswincomputing.com>
[mani: Renamed 'EIC7700' to 'ESWIN']
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
[bhelgaas: add driver tag in subject]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260227111732.1979-1-zhangsenchuan@eswincomputing.com