drm/tegra: Include <linux/i2c.h>

Include <linux/i2c.h> to get the contained declarations. No functional
changes.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sui Jingfeng <suijingfeng@loongson.cn
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/output.c

@@ -4,6 +4,7 @@
  * Copyright (C) 2012 NVIDIA CORPORATION.  All rights reserved.
  */
 
+#include <linux/i2c.h>
 #include <linux/of.h>
 
 #include <drm/drm_atomic_helper.h>