Stop including <machine/cpu-features.h>.

We're not looking at __ARM_ARCH__, because we don't support ARMv6.

Bug: http://b/18556103
Change-Id: I91fe096af697dc842a57e97515312e3530743678
diff --git a/libc/arch-arm/generic/bionic/strlen.c b/libc/arch-arm/generic/bionic/strlen.c
index 811e1e0..b9f3a2a 100644
--- a/libc/arch-arm/generic/bionic/strlen.c
+++ b/libc/arch-arm/generic/bionic/strlen.c
@@ -25,9 +25,9 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #include <string.h>
 #include <stdint.h>
-#include <machine/cpu-features.h>
 
 size_t strlen(const char *s)
 {