dt-binding: mmc: Add mmc yaml file for Sunplus SP7021

Add MMC YAML file for Sunplus SP7021.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Tony Huang <tonyhuang.sunplus@gmail.com>
Link: https://lore.kernel.org/r/8c8fbc29524819d8ab45a4fe75311b3b7b567650.1669023361.git.tonyhuang.sunplus@gmail.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/sunplus,mmc.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) Sunplus Ltd. Co. 2021
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mmc/sunplus,mmc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sunplus MMC Controller
+
+maintainers:
+  - Tony Huang <tonyhuang.sunplus@gmail.com>
+  - Li-hao Kuo <lhjeff911@gmail.com>
+
+allOf:
+  - $ref: "mmc-controller.yaml"
+
+properties:
+  compatible:
+    enum:
+      - sunplus,sp7021-mmc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - resets
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    mmc0: mmc@9c003b00 {
+        compatible = "sunplus,sp7021-mmc";
+        reg = <0x9c003b00 0x180>;
+        interrupts = <20 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clkc 0x4e>;
+        resets = <&rstc 0x3e>;
+        bus-width = <8>;
+        max-frequency = <52000000>;
+        non-removable;
+        disable-wp;
+        cap-mmc-highspeed;
+        mmc-ddr-3_3v;
+        no-sdio;
+        no-sd;
+    };

MAINTAINERS

@@ -19753,6 +19753,12 @@ W:	https://sunplus.atlassian.net/wiki/spaces/doc/overview
 F:	Documentation/devicetree/bindings/net/sunplus,sp7021-emac.yaml
 F:	drivers/net/ethernet/sunplus/
 
+SUNPLUS MMC DRIVER
+M:	Tony Huang <tonyhuang.sunplus@gmail.com>
+M:	Li-hao Kuo <lhjeff911@gmail.com>
+S:	Maintained
+F:	Documentation/devicetree/bindings/mmc/sunplus,mmc.yaml
+
 SUNPLUS OCOTP DRIVER
 M:	Vincent Shih <vincent.sunplus@gmail.com>
 S:	Maintained