dsp: Updated compatibility with the effects API

Add direct presets support to the DSP library, making it compatible
with other equalizer apps besides DSPManager (including MusicFX)

Change-Id: I2c6bf02bfdce00d21397a75683db193e8b31015a
Merge branch 'cm-10.2' of git://github.com/CyanogenMod/android_packages_apps_DSPManager into cm-10.2