arch/parisc: Detect primary video device from device instance

Update fb_is_primary device() on parisc to detect the primary display
device from the Linux device instance. Aligns the code with the other
architectures. A later patch will remove the fbdev dependency from the
function's interface.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Helge Deller <deller@gmx.de>

arch/parisc/video/fbdev.c

@@ -21,6 +21,6 @@ int fb_is_primary_device(struct fb_info *info)
 		return true;
 
 	/* return true if it's the default built-in framebuffer driver */
-	return (sti->info == info);
+	return (sti->dev == info->device);
 }
 EXPORT_SYMBOL(fb_is_primary_device);