introduce AUX build class of targets

AUX is a new class, similar to TARGET
While TARGET defines toolchain for Application Processors
AUX is defining toolchains for arbitrary utility cores (DSPs, GPUs,
MCUs, etc). This allows building of non-android sources as part
of Android tree and avoid using prebuilts if source code is avaliable

Bug: 29635686
Change-Id: Ie755ea054b16c3e86369f5fb2ba6eb0b384af77f
Signed-off-by: Alexey Polyudov <apolyudov@google.com>
diff --git a/core/config.mk b/core/config.mk
index 594c273..4ad212f 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -70,6 +70,8 @@
 BUILD_HOST_STATIC_LIBRARY:= $(BUILD_SYSTEM)/host_static_library.mk
 BUILD_HOST_SHARED_LIBRARY:= $(BUILD_SYSTEM)/host_shared_library.mk
 BUILD_STATIC_LIBRARY:= $(BUILD_SYSTEM)/static_library.mk
+BUILD_AUX_STATIC_LIBRARY:= $(BUILD_SYSTEM)/aux_static_library.mk
+BUILD_AUX_EXECUTABLE:= $(BUILD_SYSTEM)/aux_executable.mk
 BUILD_SHARED_LIBRARY:= $(BUILD_SYSTEM)/shared_library.mk
 BUILD_EXECUTABLE:= $(BUILD_SYSTEM)/executable.mk
 BUILD_HOST_EXECUTABLE:= $(BUILD_SYSTEM)/host_executable.mk