arm64: dts: renesas: condor: add PCIe support

Enable PCIe PHY and PCIEC and specify the PCIe bus clock for the Condor
board.

Based on the original (and large) patch by Vladimir Barinov.
Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm64/boot/dts/renesas/r8a77980-condor.dts

@@ -223,6 +223,18 @@ &mmc0 {
 	status = "okay";
 };
 
+&pciec {
+	status = "okay";
+};
+
+&pcie_bus_clk {
+	clock-frequency = <100000000>;
+};
+
+&pcie_phy {
+	status = "okay";
+};
+
 &pfc {
 	avb_pins: avb {
 		groups = "avb_mdio", "avb_rgmii";