build: Add QCOM target-specific config

 * Needed to support global DirectTract config on legacy targets
 * Let's also eliminate some boilerplate

Change-Id: I736c10a5e7e1f3d1e0de9e60f29b60add276f151
Merge branch 'cm-11.0' of github.com:CyanogenMod/android_build into cm-11.0