target/generic: inittab: fix devpts mounts when devtmpfs is used

If devtmpfs (the kernel-maintained /dev filesystem) is used, no
/dev/pts directory is created, causing the devpts mount to fail, which
in term causes stuff like dropbear to fail.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

target/generic/target_skeleton/etc/inittab

@@ -16,6 +16,7 @@
 # Startup the system
 null::sysinit:/bin/mount -o remount,rw /
 null::sysinit:/bin/mount -t proc proc /proc
+null::sysinit:/bin/mkdir -p /dev/pts
 null::sysinit:/bin/mount -a
 null::sysinit:/bin/hostname -F /etc/hostname
 null::sysinit:/sbin/ifconfig lo 127.0.0.1 up