PCI: rcar: Add gen3 fallback compatibility string for pcie-rcar

Add fallback compatibility string for the  R-Car Gen 3 family.  This is in
keeping with the both the existing fallback compatibility string for the
R-Car Gen 2 family and the fallback scheme being adopted wherever
appropriate for drivers for Renesas SoCs.
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

Documentation/devicetree/bindings/pci/rcar-pci.txt

@@ -7,6 +7,7 @@ compatible: "renesas,pcie-r8a7779" for the R8A7779 SoC;
 	    "renesas,pcie-r8a7793" for the R8A7793 SoC;
 	    "renesas,pcie-r8a7795" for the R8A7795 SoC;
 	    "renesas,pcie-rcar-gen2" for a generic R-Car Gen2 compatible device.
+	    "renesas,pcie-rcar-gen3" for a generic R-Car Gen3 compatible device.
 
 	    When compatible with the generic version, nodes must list the
 	    SoC-specific version corresponding to the platform first

drivers/pci/host/pcie-rcar.c

@@ -1078,6 +1078,7 @@ static const struct of_device_id rcar_pcie_of_match[] = {
 	{ .compatible = "renesas,pcie-rcar-gen2",
 	  .data = rcar_pcie_hw_init_gen2 },
 	{ .compatible = "renesas,pcie-r8a7795", .data = rcar_pcie_hw_init },
+	{ .compatible = "renesas,pcie-rcar-gen3", .data = rcar_pcie_hw_init },
 	{},
 };