phy: rcar-gen2: Add support for R-Car E2

This patch adds a compatible string to support for R-Car E2.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

Documentation/devicetree/bindings/phy/rcar-gen2-phy.txt

@@ -6,6 +6,7 @@ This file provides information on what the device node for the R-Car generation
 Required properties:
 - compatible: "renesas,usb-phy-r8a7790" if the device is a part of R8A7790 SoC.
 	      "renesas,usb-phy-r8a7791" if the device is a part of R8A7791 SoC.
+	      "renesas,usb-phy-r8a7794" if the device is a part of R8A7794 SoC.
 - reg: offset and length of the register block.
 - #address-cells: number of address cells for the USB channel subnodes, must
 		  be <1>.

drivers/phy/phy-rcar-gen2.c

@@ -195,6 +195,7 @@ static struct phy_ops rcar_gen2_phy_ops = {
 static const struct of_device_id rcar_gen2_phy_match_table[] = {
 	{ .compatible = "renesas,usb-phy-r8a7790" },
 	{ .compatible = "renesas,usb-phy-r8a7791" },
+	{ .compatible = "renesas,usb-phy-r8a7794" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, rcar_gen2_phy_match_table);