ARM: dts: msm: add 740MHz DDR frequency on 8920 target

8920 target supports DDR frequency upto 740MHz,
Add support for 740MHz DDR frequency for bandwidth mon
and devfreq cpufreq governor.

Change-Id: I0f41117e0e29647ed2d6a221aefdd5e25410674f
Signed-off-by: Santosh Mardi <gsantosh@codeaurora.org>