arm64: dts: broadcom: bcm4908: describe PMB block

PMB (Power Management Bus) controls powering connected devices (e.g.
PCIe, USB, SATA). In BCM4908 it's a part of the PROCMON block.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

arch/arm64/boot/dts/broadcom/bcm4908/bcm4908.dtsi

@@ -108,7 +108,7 @@
 		compatible = "simple-bus";
 		#address-cells = <1>;
 		#size-cells = <1>;
-		ranges = <0x00 0x00 0x80000000 0xd0000>;
+		ranges = <0x00 0x00 0x80000000 0x281000>;
 
 		usb@c300 {
 			compatible = "generic-ehci";
@@ -213,6 +213,21 @@
 				};
 			};
 		};
+
+		procmon: syscon@280000 {
+			compatible = "simple-bus";
+			reg = <0x280000 0x1000>;
+			ranges;
+
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			power-controller@2800c0 {
+				compatible = "brcm,bcm4908-pmb";
+				reg = <0x2800c0 0x40>;
+				#power-domain-cells = <1>;
+			};
+		};
 	};
 
 	bus@ff800000 {