drm: i2c: sil164: constify i2c_device_id

i2c_device_id are not supposed to change at runtime. All functions
working with i2c_device_id provided by <linux/i2c.h> work with
const i2c_device_id. So mark the non-const structs as const.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1503167300-17334-3-git-send-email-arvind.yadav.cs@gmail.com

drivers/gpu/drm/i2c/sil164_drv.c

@@ -415,7 +415,7 @@ sil164_encoder_init(struct i2c_client *client,
 	return 0;
 }
 
-static struct i2c_device_id sil164_ids[] = {
+static const struct i2c_device_id sil164_ids[] = {
 	{ "sil164", 0 },
 	{ }
 };