power: add an initial scaling_max_freq read

Added an initial read of scaling_max_freq to save that value
otherwise it gets overwritten with the top frequency from the
scaling table.

Change-Id: I3a5f576227f65687c71006dd19c321dc5ec660d4
Merge branch 'cm-10.1' of git://github.com/CyanogenMod/android_device_amazon_omap4-common into cm-10.1