arm64: dts: qcom: Add msm8916 I2C nodes.

This patch adds missing support for i2c0 and i2c6, this support is
required to connect the i2c slaves on LS expansion on DB410c.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Andy Gross <agross@codeaurora.org>