arm64: dts: renesas: falcon: Describe CAN clock

Describe the 40 MHz Crystal Clock Oscillator providing CAN_CLK.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/0bf36a1708ad87c00455b96ebaacc63fb7305b7a.1675164686.git.geert+renesas@glider.be

arch/arm64/boot/dts/renesas/r8a779a0-falcon.dts

@@ -37,8 +37,12 @@ phy0: ethernet-phy@0 {
 	};
 };
 
+&can_clk {
+	clock-frequency = <40000000>;
+};
+
 &canfd {
-	pinctrl-0 = <&canfd0_pins>, <&canfd1_pins>;
+	pinctrl-0 = <&canfd0_pins>, <&canfd1_pins>, <&can_clk_pins>;
 	pinctrl-names = "default";
 	status = "okay";
 
@@ -80,6 +84,11 @@ pins_mii {
 
 	};
 
+	can_clk_pins: can-clk {
+		groups = "can_clk";
+		function = "can_clk";
+	};
+
 	canfd0_pins: canfd0 {
 		groups = "canfd0_data";
 		function = "canfd0";