dt-bindings: i2c: spacemit: extend and validate all properties

Extend the K1 I2C properties by including generic i2c-controller schema.
and this will enable it to do the DT validation check later.

Signed-off-by: Yixun Lan <dlan@gentoo.org>
Reviewed-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
Tested-by: Alex Elder <elder@riscstar.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Documentation/devicetree/bindings/i2c/spacemit,k1-i2c.yaml

@@ -9,6 +9,9 @@ title: I2C controller embedded in SpacemiT's K1 SoC
 maintainers:
   - Troy Mitchell <troymitchell988@gmail.com>
 
+allOf:
+  - $ref: /schemas/i2c/i2c-controller.yaml#
+
 properties:
   compatible:
     const: spacemit,k1-i2c