dt-bindings: mmc: Add StarFive MMC module

Add documentation to describe StarFive designware mobile storage
host controller driver.
Signed-off-by: William Qiu <william.qiu@starfivetech.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230215113249.47727-2-william.qiu@starfivetech.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/starfive,jh7110-mmc.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mmc/starfive,jh7110-mmc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: StarFive Designware Mobile Storage Host Controller
+
+description:
+  StarFive uses the Synopsys designware mobile storage host controller
+  to interface a SoC with storage medium such as eMMC or SD/MMC cards.
+
+allOf:
+  - $ref: synopsys-dw-mshc-common.yaml#
+
+maintainers:
+  - William Qiu <william.qiu@starfivetech.com>
+
+properties:
+  compatible:
+    const: starfive,jh7110-mmc
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: biu clock
+      - description: ciu clock
+
+  clock-names:
+    items:
+      - const: biu
+      - const: ciu
+
+  interrupts:
+    maxItems: 1
+
+  starfive,sysreg:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      - items:
+          - description: phandle to System Register Controller syscon node
+          - description: offset of SYS_SYSCONSAIF__SYSCFG register for MMC controller
+          - description: shift of SYS_SYSCONSAIF__SYSCFG register for MMC controller
+          - description: mask of SYS_SYSCONSAIF__SYSCFG register for MMC controller
+    description:
+      Should be four parameters, the phandle to System Register Controller
+      syscon node and the offset/shift/mask of SYS_SYSCONSAIF__SYSCFG register
+      for MMC controller.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - interrupts
+  - starfive,sysreg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    mmc@16010000 {
+        compatible = "starfive,jh7110-mmc";
+        reg = <0x16010000 0x10000>;
+        clocks = <&syscrg 91>,
+                 <&syscrg 93>;
+        clock-names = "biu","ciu";
+        resets = <&syscrg 64>;
+        reset-names = "reset";
+        interrupts = <74>;
+        fifo-depth = <32>;
+        fifo-watermark-aligned;
+        data-addr = <0>;
+        starfive,sysreg = <&sys_syscon 0x14 0x1a 0x7c000000>;
+    };