Fix includes right throughout the Xserver tree:

change "foo.h" to <X11/foo.h> for core headers, e.g. X.h, Xpoll.h;
change "foo.h", "extensions/foo.h" and "X11/foo.h" to
    <X11/extensions/foo.h> for extension headers, e.g. Xv.h;
change "foo.[ch]" to <X11/Xtrans/foo.[ch]> for Xtrans files.

src/dummy.h

@@ -8,7 +8,7 @@
 #include "xf86Cursor.h"
 
 #include "xf86xv.h"
-#include "Xv.h"
+#include <X11/extensions/Xv.h>
 
 /* Supported chipsets */
 typedef enum {

src/dummy_driver.c

@@ -22,7 +22,7 @@
 #include "micmap.h"
 
 /* identifying atom needed by magnifiers */
-#include "Xatom.h"
+#include <X11/Xatom.h>
 #include "property.h"
 
 #include "xf86cmap.h"
@@ -34,7 +34,7 @@
 #include "picturestr.h"
 
 #include "xf86xv.h"
-#include "Xv.h"
+#include <X11/extensions/Xv.h>
 
 /*
  * Driver data structures.
@@ -42,13 +42,13 @@
 #include "dummy.h"
 
 /* These need to be checked */
-#include "X.h"
-#include "Xproto.h"
+#include <X11/X.h>
+#include <X11/Xproto.h>
 #include "scrnintstr.h"
 #include "servermd.h"
 #ifdef XFreeXDGA
 #define _XF86DGA_SERVER_
-#include "extensions/xf86dgastr.h"
+#include <X11/extensions/xf86dgastr.h>
 #endif
 
 /* Mandatory functions */