launcher: Add sysmacros.h include for major()

glibc 2.25 produces a warning when sysmacros.h is not directly included
but major() is used, as it is intended to be moved to sysmacros.h and
only there. Include it to keep the build happy.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Reviewed-by: Emilio Pozuelo Monfort <emilio.pozuelo@collabora.co.uk>
diff --git a/libweston/launcher-direct.c b/libweston/launcher-direct.c
index 4195cf6..3d8f5f6 100644
--- a/libweston/launcher-direct.c
+++ b/libweston/launcher-direct.c
@@ -33,6 +33,7 @@
 #include <unistd.h>
 #include <signal.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <sys/ioctl.h>
 #include <linux/vt.h>
 #include <linux/kd.h>
diff --git a/libweston/launcher-logind.c b/libweston/launcher-logind.c
index 8de1ed1..f10a283 100644
--- a/libweston/launcher-logind.c
+++ b/libweston/launcher-logind.c
@@ -35,6 +35,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <sys/sysmacros.h>
 #include <systemd/sd-login.h>
 #include <unistd.h>
 
diff --git a/libweston/launcher-weston-launch.c b/libweston/launcher-weston-launch.c
index 930f4e0..a7535ce 100644
--- a/libweston/launcher-weston-launch.c
+++ b/libweston/launcher-weston-launch.c
@@ -34,6 +34,7 @@
 #include <errno.h>
 #include <signal.h>
 #include <sys/socket.h>
+#include <sys/sysmacros.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/uio.h>