arm: rpi: Sync rpi dts files from Linux

Sync these files, obtained from Linux v5.15.

This adds a devicetree file for rpi_4 which was not there before.

Testing shows no change so far as I can see:
- boots to U-Boot prompt on rpi0, rpi2
- boots to distro on rpi3
- boots to distro on rpi4

I am assuming that syncing with Linux is safe, but the maintainer should
know for sure.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/dts/bcm2837-rpi-cm3.dtsi b/arch/arm/dts/bcm2837-rpi-cm3.dtsi
index 81399b2..828a205 100644
--- a/arch/arm/dts/bcm2837-rpi-cm3.dtsi
+++ b/arch/arm/dts/bcm2837-rpi-cm3.dtsi
@@ -5,9 +5,18 @@
 
 / {
 	memory@0 {
+		device_type = "memory";
 		reg = <0 0x40000000>;
 	};
 
+	leds {
+		/*
+		 * Since there is no upstream GPIO driver yet,
+		 * remove the incomplete node.
+		 */
+		/delete-node/ led-act;
+	};
+
 	reg_3v3: fixed-regulator {
 		compatible = "regulator-fixed";
 		regulator-name = "3V3";