arm64: dts: renesas: gray-hawk-single: Add CAN-FD support

Enable confirmed-working CAN-FD channels 0 and 1 on the Gray Hawk Single
development board:
  - Channel 0 uses an NXP TJR1443AT CAN transceiver, which must be
    enabled through a GPIO,
  - Channels 1-3 use Microchip MCP2558FD-H/SN CAN transceivers, which do
    not need explicit description, but channels 2-3 do not seem to work.

Inspired by a patch for Gray Hawk in the BSP by Duy Nguyen.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/7c2a06b7abec4ce1025761003ccdbce559789708.1722519717.git.geert+renesas@glider.be

arch/arm64/boot/dts/renesas/r8a779h0-gray-hawk-single.dts

@@ -47,6 +47,13 @@ aliases {
 		ethernet0 = &avb0;
 	};
 
+	can_transceiver0: can-phy0 {
+		compatible = "nxp,tjr1443";
+		#phy-cells = <0>;
+		enable-gpios = <&gpio1 3 GPIO_ACTIVE_HIGH>;
+		max-bitrate = <5000000>;
+	};
+
 	chosen {
 		bootargs = "ignore_loglevel rw root=/dev/nfs ip=on";
 		stdout-path = "serial0:921600n8";
@@ -174,6 +181,25 @@ phy0: ethernet-phy@0 {
 	};
 };
 
+&can_clk {
+	clock-frequency = <40000000>;
+};
+
+&canfd {
+	pinctrl-0 = <&canfd0_pins>, <&canfd1_pins>, <&can_clk_pins>;
+	pinctrl-names = "default";
+	status = "okay";
+
+	channel0 {
+		status = "okay";
+		phys = <&can_transceiver0>;
+	};
+
+	channel1 {
+		status = "okay";
+	};
+};
+
 &extal_clk {
 	clock-frequency = <16666666>;
 };
@@ -305,6 +331,21 @@ pins_mii {
 		};
 	};
 
+	can_clk_pins: can-clk {
+		groups = "can_clk";
+		function = "can_clk";
+	};
+
+	canfd0_pins: canfd0 {
+		groups = "canfd0_data";
+		function = "canfd0";
+	};
+
+	canfd1_pins: canfd1 {
+		groups = "canfd1_data";
+		function = "canfd1";
+	};
+
 	hscif0_pins: hscif0 {
 		groups = "hscif0_data", "hscif0_ctrl";
 		function = "hscif0";