fbdev: Include <linux/io.h> in various drivers

The code uses writel() and similar I/O-memory helpers. Include
the header file to get the declarations.

Signed-off-by: Thomas Zimmermann <[e-mail]>
Reviewed-by: Arnd Bergmann <[e-mail]>
Reviewed-by: Sam Ravnborg <[e-mail]>
Reviewed-by: Sui Jingfeng <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/video/fbdev/arcfb.c

···
 #include <linux/vmalloc.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
+#include <linux/io.h>
 #include <linux/fb.h>
 #include <linux/init.h>
 #include <linux/arcfb.h>

drivers/video/fbdev/aty/atyfb.h

···
  *  ATI Frame Buffer Device Driver Core Definitions
  */
 
+#include <linux/io.h>
 #include <linux/spinlock.h>
 #include <linux/wait.h>
+
     /*
      *  Elements of the hardware specific atyfb_par structure
      */

drivers/video/fbdev/wmt_ge_rops.c

···
 
 #include <linux/module.h>
 #include <linux/fb.h>
+#include <linux/io.h>
 #include <linux/platform_device.h>
+
 #include "core/fb_draw.h"
 #include "wmt_ge_rops.h"