dt-bindings: i2c: qcom-cci: Document SC7280 compatible

Document the compatible for the CCI block found on SC7280 SoC.

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>