[nrf fromtree] dts: bindings: power-domain: add binding for NXP's SCU-managed PDs

Add DT binding for NXP's SCU-managed PDs. This binding describes
exactly _one_ power domain.

Signed-off-by: Laurentiu Mihalcea <[email protected]>
(cherry picked from commit fb84f4f)

Author: LaurentiuM1234

dts/bindings/power-domain/nxp,scu-pd.yaml

@@ -0,0 +1,17 @@
+# Copyright 2024 NXP
+# SPDX-License-Identifier: Apache-2.0
+
+description: NXP SCU-managed power domain
+
+compatible: "nxp,scu-pd"
+
+include: power-domain.yaml
+
+properties:
+  nxp,resource-id:
+    type: int
+    required: true
+    description:
+      Number used by the firmware running on the SCU to identify
+      the resource on which the PD-related operations are to be
+      performed.