usb: xhci-rcar: Add support for R8A774A1 SoC

The R8A774A1 is compatible with the generic rcar-gen3-xhci controller.
This patch adds the compatibility flag, to support the xHCI controller.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
diff --git a/drivers/usb/host/xhci-rcar.c b/drivers/usb/host/xhci-rcar.c
index 8fc51df..5379dba 100644
--- a/drivers/usb/host/xhci-rcar.c
+++ b/drivers/usb/host/xhci-rcar.c
@@ -146,6 +146,7 @@
 }
 
 static const struct udevice_id xhci_rcar_ids[] = {
+	{ .compatible = "renesas,rcar-gen3-xhci" },
 	{ .compatible = "renesas,xhci-r8a7795" },
 	{ .compatible = "renesas,xhci-r8a7796" },
 	{ .compatible = "renesas,xhci-r8a77965" },