dt-bindings: can: rcar_can: Add r8a774a1 support

Document RZ/G2M (r8a774a1) SoC specific bindings.
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Chris Paterson <Chris.Paterson2@renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Documentation/devicetree/bindings/net/can/rcar_can.txt

@@ -5,6 +5,7 @@ Required properties:
 - compatible: "renesas,can-r8a7743" if CAN controller is a part of R8A7743 SoC.
 	      "renesas,can-r8a7744" if CAN controller is a part of R8A7744 SoC.
 	      "renesas,can-r8a7745" if CAN controller is a part of R8A7745 SoC.
+	      "renesas,can-r8a774a1" if CAN controller is a part of R8A774A1 SoC.
 	      "renesas,can-r8a7778" if CAN controller is a part of R8A7778 SoC.
 	      "renesas,can-r8a7779" if CAN controller is a part of R8A7779 SoC.
 	      "renesas,can-r8a7790" if CAN controller is a part of R8A7790 SoC.
@@ -18,15 +19,21 @@ Required properties:
 	      "renesas,rcar-gen1-can" for a generic R-Car Gen1 compatible device.
 	      "renesas,rcar-gen2-can" for a generic R-Car Gen2 or RZ/G1
 	      compatible device.
-	      "renesas,rcar-gen3-can" for a generic R-Car Gen3 compatible device.
+	      "renesas,rcar-gen3-can" for a generic R-Car Gen3 or RZ/G2
+	      compatible device.
 	      When compatible with the generic version, nodes must list the
 	      SoC-specific version corresponding to the platform first
 	      followed by the generic version.
 
 - reg: physical base address and size of the R-Car CAN register map.
 - interrupts: interrupt specifier for the sole interrupt.
-- clocks: phandles and clock specifiers for 3 CAN clock inputs.
-- clock-names: 3 clock input name strings: "clkp1", "clkp2", "can_clk".
+- clocks: phandles and clock specifiers for 2 CAN clock inputs for RZ/G2
+	  devices.
+	  phandles and clock specifiers for 3 CAN clock inputs for every other
+	  SoC.
+- clock-names: 2 clock input name strings for RZ/G2: "clkp1", "can_clk".
+	       3 clock input name strings for every other SoC: "clkp1", "clkp2",
+	       "can_clk".
 - pinctrl-0: pin control group to be used for this controller.
 - pinctrl-names: must be "default".
 
@@ -42,8 +49,9 @@ using the below properties:
 Optional properties:
 - renesas,can-clock-select: R-Car CAN Clock Source Select. Valid values are:
 			    <0x0> (default) : Peripheral clock (clkp1)
-			    <0x1> : Peripheral clock (clkp2)
-			    <0x3> : Externally input clock
+			    <0x1> : Peripheral clock (clkp2) (not supported by
+				    RZ/G2 devices)
+			    <0x3> : External input clock
 
 Example
 -------