dts: nordic: specify device model of global hsfll clock

Add specific device model for global hsfll clock and update dts tree
to use specific model. The clock is not fixed, and configurable at
runtime to predefined frequencies specified by the platform.

Signed-off-by: Bjarki Arge Andreasen <bjarki.andreasen@nordicsemi.no>

dts/bindings/clock/nordic,nrf-hsfll-global.yaml

@@ -0,0 +1,44 @@
+# Copyright (c) 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  Nordic Global HSFLL clock.
+
+  The lowest supported clock frequency is the default
+  clock frequency.
+
+  Example:
+
+    global_hsfll: global_hsfll {
+            compatible = "nordic,nrf-hsfll-global";
+            clocks = <&fll16>;
+            #clock-cells = <0>;
+            clock-frequency = <320000000>;
+            supported-clock-frequencies = <64000000
+                                           128000000
+                                           256000000
+                                           320000000>;
+    };
+
+compatible: "nordic,nrf-hsfll-global"
+
+include:
+  - "base.yaml"
+  - "clock-controller.yaml"
+
+properties:
+  clocks:
+    required: true
+
+  "#clock-cells":
+    const: 0
+
+  supported-clock-frequencies:
+    type: array
+    description: Supported clock frequencies in ascending order
+
+  clock-frequency:
+    type: int
+    description: |
+      Optional fixed frequency specified if used in fixed
+      frequency mode.

dts/common/nordic/nrf54h20.dtsi

@@ -182,10 +182,14 @@
 		};
 
 		hsfll120: hsfll120 {
-			compatible = "fixed-clock";
+			compatible = "nordic,nrf-hsfll-global";
 			clocks = <&fll16m>;
 			#clock-cells = <0>;
-			clock-frequency = <DT_FREQ_M(320)>;
+			clock-frequency = <320000000>;
+			supported-clock-frequencies = <64000000
+						       128000000
+						       256000000
+						       320000000>;
 		};
 
 		lfclk: lfclk {