ARM: dts: hammerhead: Change i2c clock rate to 19.2 MHz

* Referenced CAF:
  https://www.codeaurora.org/cgit/quic/la/kernel/msm/commit/arch/arm/boot/dts/msm8974.dtsi?h=kk_3.5&id=2762366bdeb1d2d3bb43ffb21ad3a0908d51551e

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
ASoC: sound_control: Cleanup

* Clean up unused function. I believe this was implemented to
  prevent kernel from changing value itself. However, this is now
  done gracefully by sound control lock.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>