ARM: dts: enable PCIe support for Cygnus

Add PCIe device nodes in bcm-cygnus.dtsi but keep them disabled there.
Only enable them for bcm958300k where PCIe interfaces are populated

Signed-off-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

arch/arm/boot/dts/bcm958300k.dts

@@ -47,6 +47,14 @@
 		bootargs = "console=ttyS0,115200";
 	};
 
+	pcie0: pcie@18012000 {
+		status = "okay";
+	};
+
+	pcie1: pcie@18013000 {
+		status = "okay";
+	};
+
 	uart3: serial@18023000 {
 		status = "okay";
 	};