Rewrite atomic.h to use stdatomic.h.

Replace atomic-inl.h with a file that just includes atomic.h.
Remove platform specific implementations.

Change-Id: If16d74fbe0af7836ed8c1296c17e13a2d0d20f64
diff --git a/libcutils/atomic.c b/libcutils/atomic.c
index 1484ef8..d34aa00 100644
--- a/libcutils/atomic.c
+++ b/libcutils/atomic.c
@@ -14,6 +14,13 @@
  * limitations under the License.
  */
 
+/*
+ * Generate non-inlined versions of android_atomic functions.
+ * Nobody should be using these, but some binary blobs currently (late 2014)
+ * are.
+ * If you read this in 2015 or later, please try to delete this file.
+ */
+
 #define ANDROID_ATOMIC_INLINE
 
-#include <cutils/atomic-inline.h>
+#include <cutils/atomic.h>