i2c-qup allows using DMA to speed up larger transfers. In msm8916.dtsi
the DMA channels are already assigned to the SPI controllers but
missing for I2C. Add them there as well.

This also fixes confusing errors in dmesg for each I2C controller:
  i2c_qup 78b6000.i2c: tx channel not available
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230107110958.5762-3-stephan@gerhold.net