rs: DON'T use stock clang headers when building with a prebuilt!

Change-Id: I86f730db8f7739b47cc7755d6668512e5952eb26
Signed-off-by: bart452 <bart4524@gmail.com>
Merge "rs: DON'T use stock clang headers when building with a prebuilt!" into kk44
Revert "Revert "CLANG: Workaround for violations on unsupported command -mtune=cortex-a15""

clang-3.4: error: unsupported mtune='cortex-a15', mtune flag ignored.
make: *** [/media/VANIR/Vanir42/out/target/product/klte/obj/SHARED_LIBRARIES/libRS_intermediates/rsAdapter.o] Error 1
make: *** Waiting for unfinished jobs....

This reverts commit 5b3f556af75f486c2a7cb1e3e0aa29ad60eff1be.

Change-Id: Ia0476e3e11caf78a9953265856df1e14c4cdd239
Wildcardify mtune fix

Change-Id: I91f972518285f948795f229ec8cabba3b9108e52
Add missing header stdbool.h to fix error from:
rs: DON'T use stock clang headers when building with a prebuilt!

Change-Id: I190886aeb9651919b7c7cb65a4548f20cb783460