regulator: Add bindings for MediaTek DVFSRC Regulators

The Dynamic Voltage and Frequency Scaling Resource Collector Regulators
are controlled with votes to the DVFSRC hardware.

This adds support for the regulators found in MT6873, MT8183, MT8192
and MT8195 SoCs.
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patch.msgid.link/20240610085735.147134-2-angelogioacchino.delregno@collabora.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/mediatek,mt6873-dvfsrc-regulator.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/mediatek,mt6873-dvfsrc-regulator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek DVFSRC-controlled Regulators
+
+description:
+  The Dynamic Voltage and Frequency Scaling Resource Collector Regulators
+  are controlled with votes to the DVFSRC hardware.
+
+maintainers:
+  - AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
+
+properties:
+  compatible:
+    enum:
+      - mediatek,mt6873-dvfsrc-regulator
+      - mediatek,mt8183-dvfsrc-regulator
+      - mediatek,mt8192-dvfsrc-regulator
+      - mediatek,mt8195-dvfsrc-regulator
+
+  dvfsrc-vcore:
+    description: DVFSRC-controlled SoC Vcore regulator
+    $ref: regulator.yaml#
+    unevaluatedProperties: false
+
+  dvfsrc-vscp:
+    description: DVFSRC-controlled System Control Processor regulator
+    $ref: regulator.yaml#
+    unevaluatedProperties: false
+
+required:
+  - compatible
+
+anyOf:
+  - required:
+      - dvfsrc-vcore
+  - required:
+      - dvfsrc-vscp
+
+additionalProperties: false