libmix: Use include-path-for MACRO for AOSP includes

BZ: 160780

Instead of hardcoding the AOSP include paths from top of Android
Build Tree, need to use include-path-for MACRO defined in
build/core/pathmap.mk. It also defines the a mapping of project
names to the path.
New paths can be added in device/intel/common/BoardConfig.mk

Change-Id: I7dc15ee6ad769bd8c260dabe14149f15e77da71c
Signed-off-by: Chetan Rao <chetan.rao@intel.com>
2 files changed