dt-bindings: i2c: atmel,at91sam: correct path to i2c-controller schema

The referenced i2c-controller.yaml schema is provided by dtschema
package (outside of Linux kernel), so use full path to reference it.

Cc: [email protected]
Fixes: 7ea75dd ("dt-bindings: i2c: convert i2c-at91 to json-schema")
Signed-off-by: Krzysztof Kozlowski <[email protected]>
Reviewed-by: Conor Dooley <[email protected]>
Signed-off-by: Andi Shyti <[email protected]>

Documentation/devicetree/bindings/i2c/atmel,at91sam-i2c.yaml

@@ -77,7 +77,7 @@ required:
  - clocks
 
 allOf:
- - $ref: i2c-controller.yaml
+ - $ref: /schemas/i2c/i2c-controller.yaml#
  - if:
  properties:
  compatible: