dt-bindings: i2c: qcom-cci: add QCOM MSM8974 compatible

Add the compatible for the CCI found in MSM8974 which supports two I2C
masters.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>