dt-bindings: phy: add binding for the i.MX8MP HDMI PHY

Add a DT binding for the HDMI PHY found on the i.MX8MP SoC.
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Tommaso Merciai <tomm.merciai@gmail.com>
Link: https://lore.kernel.org/r/20240227220444.77566-2-aford173@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/phy/fsl,imx8mp-hdmi-phy.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/phy/fsl,imx8mp-hdmi-phy.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Freescale i.MX8MP HDMI PHY
+
+maintainers:
+  - Lucas Stach <l.stach@pengutronix.de>
+
+properties:
+  compatible:
+    enum:
+      - fsl,imx8mp-hdmi-phy
+
+  reg:
+    maxItems: 1
+
+  "#clock-cells":
+    const: 0
+
+  clocks:
+    maxItems: 2
+
+  clock-names:
+    items:
+      - const: apb
+      - const: ref
+
+  "#phy-cells":
+    const: 0
+
+  power-domains:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - "#clock-cells"
+  - clocks
+  - clock-names
+  - "#phy-cells"
+  - power-domains
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/clock/imx8mp-clock.h>
+    #include <dt-bindings/power/imx8mp-power.h>
+
+    phy@32fdff00 {
+        compatible = "fsl,imx8mp-hdmi-phy";
+        reg = <0x32fdff00 0x100>;
+        clocks = <&clk IMX8MP_CLK_HDMI_APB>,
+                 <&clk IMX8MP_CLK_HDMI_24M>;
+        clock-names = "apb", "ref";
+        power-domains = <&hdmi_blk_ctrl IMX8MP_HDMIBLK_PD_HDMI_TX_PHY>;
+        #clock-cells = <0>;
+        #phy-cells = <0>;
+    };