Removes references to mibstore.h and miInitializeBackingStore, which
have been removed from xorg-server.  Zack Rusin <zackr@vmware.com>
wrote: "It was a noop for at least 5 years and it has been removed."
See: http://patches.openembedded.org/patch/46133/

--- xf86-video-i128-1.3.6/src/i128_driver.c.~1~	2012-07-17 01:21:15.000000000 -0400
+++ xf86-video-i128-1.3.6/src/i128_driver.c	2014-12-19 00:47:16.140087736 -0500
@@ -51,7 +51,6 @@
 #include "mipointer.h"
 
 /* All drivers implementing backing store need this */
-#include "mibstore.h"
 #include "micmap.h"
 
 #include "xf86DDC.h"
@@ -1557,7 +1556,6 @@
         return FALSE;
     }
     
-    miInitializeBackingStore(pScreen);
     xf86SetBackingStore(pScreen);
     xf86SetSilkenMouse(pScreen);
 
