ARM: dts: msm: Add support for ddr and cci scaling for msm8937

Add devfreq node to add mapping for cpubw and cci frequency
against corresponding cpu frequency corner to allow ddr bw and
cci scaling.

Change-Id: I72efc3f439e9c6331c5d900a4b51f60928037047
Signed-off-by: Hanumath Prasad <hpprasad@codeaurora.org>