core: move definition of NMLinkType to nm-types.h

As we use NMLinkType in NetworkManagerUtils.h, we cannot use
the utils header without nm-platform.h. That is clearly wrong.
Apparently NMLinkType has a wider use outside of platform (and
its name is not prefixed with 'platform' either).

Move the enum definition to nm-types.h.

Signed-off-by: Thomas Haller <thaller@redhat.com>

src/dhcp-manager/nm-dhcp-systemd.c

@@ -37,6 +37,7 @@
 #include "nm-dhcp-utils.h"
 #include "NetworkManagerUtils.h"
 #include "gsystem-local-alloc.h"
+#include "nm-platform.h"
 
 #include "nm-sd-adapt.h"