exec: move include files to include/exec/

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/xen-stub.c b/xen-stub.c
index 9214392..1ee8411 100644
--- a/xen-stub.c
+++ b/xen-stub.c
@@ -10,7 +10,7 @@
 
 #include "qemu-common.h"
 #include "hw/xen.h"
-#include "memory.h"
+#include "exec/memory.h"
 #include "qmp-commands.h"
 
 void xenstore_store_pv_console_info(int i, CharDriverState *chr)