PCI: rcar: Use proper name for the R-Car SoC

It is 'R-Car', not 'RCar'. No code or binding changes, only descriptive
text.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>

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

-* Renesas RCar PCIe interface
+* Renesas R-Car PCIe interface
 
 Required properties:
 compatible: "renesas,pcie-r8a7779" for the R8A7779 SoC;