[media] rcar_jpu: Add R-Car Gen2 Fallback Compatibility String

Add fallback compatibility string.
This is in keeping with the fallback scheme being adopted wherever
appropriate for drivers for Renesas SoCs.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

Documentation/devicetree/bindings/media/renesas,jpu.txt

@@ -5,11 +5,12 @@ and decoding function conforming to the JPEG baseline process, so that the JPU
 can encode image data and decode JPEG data quickly.
 
 Required properties:
-  - compatible: should containg one of the following:
-			- "renesas,jpu-r8a7790" for R-Car H2
-			- "renesas,jpu-r8a7791" for R-Car M2-W
-			- "renesas,jpu-r8a7792" for R-Car V2H
-			- "renesas,jpu-r8a7793" for R-Car M2-N
+- compatible: "renesas,jpu-<soctype>", "renesas,rcar-gen2-jpu" as fallback.
+	Examples with soctypes are:
+	  - "renesas,jpu-r8a7790" for R-Car H2
+	  - "renesas,jpu-r8a7791" for R-Car M2-W
+	  - "renesas,jpu-r8a7792" for R-Car V2H
+	  - "renesas,jpu-r8a7793" for R-Car M2-N
 
   - reg: Base address and length of the registers block for the JPU.
   - interrupts: JPU interrupt specifier.
@@ -17,7 +18,7 @@ Required properties:
 
 Example: R8A7790 (R-Car H2) JPU node
 	jpeg-codec@fe980000 {
-		compatible = "renesas,jpu-r8a7790";
+		compatible = "renesas,jpu-r8a7790", "renesas,rcar-gen2-jpu";
 		reg = <0 0xfe980000 0 0x10300>;
 		interrupts = <0 272 IRQ_TYPE_LEVEL_HIGH>;
 		clocks = <&mstp1_clks R8A7790_CLK_JPU>;

drivers/media/platform/rcar_jpu.c

@@ -1613,6 +1613,7 @@ static const struct of_device_id jpu_dt_ids[] = {
 	{ .compatible = "renesas,jpu-r8a7791" }, /* M2-W */
 	{ .compatible = "renesas,jpu-r8a7792" }, /* V2H */
 	{ .compatible = "renesas,jpu-r8a7793" }, /* M2-N */
+	{ .compatible = "renesas,rcar-gen2-jpu" },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, jpu_dt_ids);