ramips: mt7621-dts: add missing device_type in pcie root ports

According to the YAML schema 'pci-bus.yaml' the 'device_type'
property is mandatory for all pcie root ports. Hence add it.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20210506170742.28196-3-sergio.paracuellos@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

target/linux/ramips/dts/mt7621.dtsi

@@ -578,6 +578,7 @@
 			reg = <0x0000 0 0 0 0>;
 			#address-cells = <3>;
 			#size-cells = <2>;
+			device_type = "pci";
 			ranges;
 		};
 
@@ -585,6 +586,7 @@
 			reg = <0x0800 0 0 0 0>;
 			#address-cells = <3>;
 			#size-cells = <2>;
+			device_type = "pci";
 			ranges;
 		};
 
@@ -592,6 +594,7 @@
 			reg = <0x1000 0 0 0 0>;
 			#address-cells = <3>;
 			#size-cells = <2>;
+			device_type = "pci";
 			ranges;
 		};
 	};