dt-bindings: can: rcar_can: Add r8a774a1 support

- 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.

	      "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".

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

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