small fix on cmakedefine of bitmap resolution

dmm_config.h.in

@@ -41,7 +41,7 @@
 #ifdef BITMAP_RB_ONLY
 
 /** How many bytes per cell should be used */
-#cmakedefine BITMAP_RESOLUTION
+#cmakedefine BITMAP_RESOLUTION @BITMAP_RESOLUTION@
 
 #endif /* BITMAP_RB_ONLY */