Fix 'make depend' for out of the source tree build.

diff --git a/configure b/configure
index ee69347..c10b8d1 100755
--- a/configure
+++ b/configure
@@ -7595,6 +7595,7 @@
 dlls/dinput/keyboard \
 dlls/dinput/mouse \
 dlls/kernel/messages \
+dlls/user/dde \
 dlls/user/resources \
 dlls/wineps/data \
 "
diff --git a/configure.in b/configure.in
index b896b921..fca9d5c 100644
--- a/configure.in
+++ b/configure.in
@@ -1201,6 +1201,7 @@
 dlls/dinput/keyboard \
 dlls/dinput/mouse \
 dlls/kernel/messages \
+dlls/user/dde \
 dlls/user/resources \
 dlls/wineps/data \
 "
diff --git a/dlls/user/dde/client.c b/dlls/user/dde/client.c
index 706ac0b..1086c42 100644
--- a/dlls/user/dde/client.c
+++ b/dlls/user/dde/client.c
@@ -19,7 +19,7 @@
 #include "dde.h"
 #include "ddeml.h"
 #include "debugtools.h"
-#include "dde_private.h"
+#include "dde/dde_private.h"
 
 DEFAULT_DEBUG_CHANNEL(ddeml);
 
diff --git a/dlls/user/dde/misc.c b/dlls/user/dde/misc.c
index a9e55d7..3f80f78 100644
--- a/dlls/user/dde/misc.c
+++ b/dlls/user/dde/misc.c
@@ -19,7 +19,7 @@
 #include "dde.h"
 #include "ddeml.h"
 #include "debugtools.h"
-#include "dde_private.h"
+#include "dde/dde_private.h"
 
 DEFAULT_DEBUG_CHANNEL(ddeml);
 
diff --git a/dlls/user/dde/server.c b/dlls/user/dde/server.c
index 5d3248e..656bbc9 100644
--- a/dlls/user/dde/server.c
+++ b/dlls/user/dde/server.c
@@ -19,7 +19,7 @@
 #include "dde.h"
 #include "ddeml.h"
 #include "debugtools.h"
-#include "dde_private.h"
+#include "dde/dde_private.h"
 
 DEFAULT_DEBUG_CHANNEL(ddeml);