<sys/time.h> should include [most of] <sys/select.h>.

Found by trying to build c-ares with bionic.

Change-Id: I38684abcb806ef1e8806c68b4a6dd9200f48849e
diff --git a/libc/include/sys/time.h b/libc/include/sys/time.h
index 67107c6..f60c905 100644
--- a/libc/include/sys/time.h
+++ b/libc/include/sys/time.h
@@ -25,6 +25,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+
 #ifndef _SYS_TIME_H_
 #define _SYS_TIME_H_
 
@@ -32,6 +33,9 @@
 #include <sys/types.h>
 #include <linux/time.h>
 
+/* POSIX says <sys/time.h> gets you most of <sys/select.h> and may get you all of it. */
+#include <sys/select.h>
+
 __BEGIN_DECLS
 
 extern int gettimeofday(struct timeval *, struct timezone *);