[PATCH] visws framebuffer driver needs mm.h

This fixes the visws framebuffer driver which needs vm_area_struct from
linux/mm.h

drivers/video/sgivwfb.c

@@ -12,6 +12,7 @@
 #include <linux/config.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
+#include <linux/mm.h>
 #include <linux/errno.h>
 #include <linux/delay.h>
 #include <linux/fb.h>