fbdev: hitfb: Fix integer-to-pointer cast

Fix the type casting from unsigned long to char __iomem *. Resolves
the following warning:

../drivers/video/fbdev/hitfb.c:411:27: warning: incorrect type in assignment (different address spaces)
../drivers/video/fbdev/hitfb.c:411:27:    expected char [noderef] __iomem *screen_base
../drivers/video/fbdev/hitfb.c:411:27:    got void *
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>

drivers/video/fbdev/hitfb.c

@@ -392,7 +392,7 @@ static int hitfb_probe(struct platform_device *dev)
 	info->flags = FBINFO_DEFAULT | FBINFO_HWACCEL_YPAN |
 		FBINFO_HWACCEL_FILLRECT | FBINFO_HWACCEL_COPYAREA;
 
-	info->screen_base = (void *)hitfb_fix.smem_start;
+	info->screen_base = (char __iomem *)(uintptr_t)hitfb_fix.smem_start;
 
 	ret = fb_alloc_cmap(&info->cmap, 256, 0);
 	if (unlikely(ret < 0))