dt-bindings: mmc: Add sdhci support for Canaan k230

The Canaan k230 uses the SDHCI from Synopsys. Add compatible strings
to the k230. The k230 has two controllers. MMC0 supports eMMC, while
MMC1 supports SDIO.

Signed-off-by: Jiayu Du <jiayu.riscv@isrc.iscas.ac.cn>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml

@@ -23,6 +23,8 @@ properties:
           - const: sophgo,sg2044-dwcmshc
           - const: sophgo,sg2042-dwcmshc
       - enum:
+          - canaan,k230-emmc
+          - canaan,k230-sdio
           - hpe,gsc-dwcmshc
           - rockchip,rk3568-dwcmshc
           - rockchip,rk3588-dwcmshc
@@ -58,6 +60,11 @@ properties:
     minItems: 4
     maxItems: 5
 
+  canaan,usb-phy:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description: Phandle to the Canaan K230 USB PHY node required for
+                 k230-emmc/sdio.
+
   rockchip,txclk-tapnum:
     description: Specify the number of delay for tx sampling.
     $ref: /schemas/types.yaml#/definitions/uint8
@@ -101,6 +108,27 @@ required:
 allOf:
   - $ref: mmc-controller.yaml#
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - canaan,k230-emmc
+              - canaan,k230-sdio
+    then:
+      properties:
+        clocks:
+          minItems: 5
+        clock-names:
+          items:
+            - const: core
+            - const: bus
+            - const: axi
+            - const: block
+            - const: timer
+      required:
+        - canaan,usb-phy
+
   - if:
       properties:
         compatible: