dspmanager: Allow target to provide it's own replacement

 * We may want to have an external package which provides
   it's own effects configuration as well as the effects
   app itself. Add support for this.

Change-Id: Ifa39b171f3e13902781b91537c422697dc2d0228
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_packages_apps_DSPManager into kitkat