build: Add QCOM target-specific config

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

Change-Id: I736c10a5e7e1f3d1e0de9e60f29b60add276f151

Conflicts:
	core/config.mk
build: Fix cflags for QC targets

Change-Id: I2281bec3afb4d80e80845718d880dc24ef7baf32
Merge https://github.com/AOSP-S4-KK/platform_build into kk-4.4