Add <linux/tty.h> to libc/include/sys/ioctl.h

This is the change to export the tty ldisc definitions (like N_TTY)
from Linux uapi kernel header. So bionic is compatbile with glibc
which has its own tty ldisc definition exported through ioctl.h

Change-Id: I44e4c7cc2eba31549e9c9c75f74961a949d4a696
Signed-off-by: Qiming Shi <qiming.shi@intel.com>
Signed-off-by: Yin, Fengwei <fengwei.yin@intel.com>
diff --git a/libc/include/sys/ioctl.h b/libc/include/sys/ioctl.h
index 49d452c..a1014dc 100644
--- a/libc/include/sys/ioctl.h
+++ b/libc/include/sys/ioctl.h
@@ -38,6 +38,7 @@
 #include <asm/ioctls.h>
 #include <asm/termbits.h>
 #include <sys/ioctl_compat.h>
+#include <linux/tty.h>
 
 __BEGIN_DECLS