Deal with CM changing vars (WITH_QC_PERF) for no reason, and still be able to
use future changes where they use TARGET_HAVE_QC_PERF without difficulty.

Change-Id: I46f8eb031f03e859561dae32401cebf328e05274
build: qcom: Set QCOM_*_PATH variables for hardware/qcom-* projects

This consolidates a bunch of one-off logic scattered throughout the
code base.  Usage in Android.mk files is trivial:

At top level, use e.g. "ifeq ($(call my-dir),$(QCOM_AUDIO_PATH))".
This works for all variants, including non-variants (i.e. AOSP).

Within subdirs, use e.g. hardware/qcom/audio => $(QCOM_AUDIO_PATH)

Change-Id: Iee2497ea9a7efeb4ae9e861b84c532b19da7b69d
[WIP]: New changes needed for msm-3.5 clang

Change-Id: If41682c7265645056be757e58eb14b8707ce7438