dt-bindings: mmc: rockchip-dw-mshc: add description for rk3308

The description below is already in use for rk3308.dtsi,
but was somehow never added to a document, so add
"rockchip,rk3308-dw-mshc", "rockchip,rk3288-dw-mshc"
for mmc nodes on a rk3308 platform to rockchip-dw-mshc.yaml.

Signed-off-by: Johan Jonker <[email protected]>
Acked-by: Rob Herring <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>

Author: Johan Jonker

Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml

@@ -35,6 +35,8 @@ properties:
             - rockchip,rk3036-dw-mshc
             # for Rockchip RK322x
             - rockchip,rk3228-dw-mshc
+            # for Rockchip RK3308
+            - rockchip,rk3308-dw-mshc
             # for Rockchip RK3328
             - rockchip,rk3328-dw-mshc
             # for Rockchip RK3368