arm64: dts: renesas: r9a09g056n48-rzv2n-evk: Enable PCIe

Enable the PCIE1 slot available on the RZ/V2N EVK.

Note, the PCIE_REFCLK comes from 5L35023B versa clock generator, once the
support for this clock generator is added, the fixed clock node can be
removed and can be replaced with a reference to the clock generator.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260501105116.33452-3-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Author: prabhakarlad

arch/arm64/boot/dts/renesas/r9a09g056n48-rzv2n-evk.dts

@@ -63,6 +63,12 @@
 		reg = <0x0 0x48000000 0x1 0xf8000000>;
 	};
 
+	pcie_refclk: clock-pcie-ref {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <100000000>;
+	};
+
 	reg_0p8v: regulator-0p8v {
 		compatible = "regulator-fixed";
 		regulator-name = "fixed-0.8V";
@@ -333,6 +339,17 @@
 	status = "okay";
 };
 
+&pcie {
+	pinctrl-0 = <&pcie_pins>;
+	pinctrl-names = "default";
+	status = "okay";
+};
+
+&pcie_port0 {
+	clocks = <&pcie_refclk>;
+	clock-names = "ref";
+};
+
 &pinctrl {
 	eth0_pins: eth0 {
 		pins = "ET0_TXC_TXCLK";
@@ -383,6 +400,12 @@
 			 <RZV2N_PORT_PINMUX(0, 7, 1)>; /* I2C8_SCL */
 	};
 
+	pcie_pins: pcie {
+		pins = "PCIE0_RSTOUTB";
+		slew-rate = <0>;
+		renesas,output-impedance = <2>;
+	};
+
 	scif_pins: scif {
 		pins = "SCIF_TXD", "SCIF_RXD";
 		renesas,output-impedance = <1>;