ARM: dts: msm: i2c: change  clock rate to 19.2 MHz

For standard  requirement, I2C source
speed of 50MHz causes high power usage, hence
this patch change the clock rate to 19.2 MHz
to save power.

Signed-off-by: Sana Venkat Raju <c_vsana@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Chet Kener <Cl3Kener@gmail.com>

Change-Id: Ia489965a3d8013dd514eb8196d721fbe4b4c25d1