Add the CM DSP library to the device-specific effects table

Copied from a pull request to my repo by klusark.  Credit to him.
Consolidate Recovery settings and add QCOM bits
Update extract-files.sh to allow pulling from disk (factory images)
Fix mkbootimg.mk to include all revisions of msm8974-hammerhead

Multiple DTBs are supported in a single DT image and the appropriate
one will be picked based SOC revision, etc
Update props