Input: elants_i2c - fix NULL dereference at probing

The recent change in elants_i2c driver to support more chips
introduced a regression leading to Oops at probing. The driver reads
id->driver_data, but the id may be NULL depending on the device type
the driver gets bound.

Replace the driver data extraction with the device_get_match_data()
helper, and define the driver data in OF table, too.

Fixes: 9517b95bdc46 ("Input: elants_i2c - add support for eKTF3624")
BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1186454
Signed-off-by: Takashi Iwai <[e-mail]>
Cc: <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/touchscreen/elants_i2c.c

···
 	init_completion(&ts->cmd_done);
 
 	ts->client = client;
-	ts->chip_id = (enum elants_chip_id)id->driver_data;
+	ts->chip_id = (enum elants_chip_id)(uintptr_t)device_get_match_data(&client->dev);
 	i2c_set_clientdata(client, ts);
 
 	ts->vcc33 = devm_regulator_get(&client->dev, "vcc33");
···
 
 #ifdef CONFIG_OF
 static const struct of_device_id elants_of_match[] = {
-	{ .compatible = "elan,ekth3500" },
-	{ .compatible = "elan,ektf3624" },
+	{ .compatible = "elan,ekth3500", .data = (void *)EKTH3500 },
+	{ .compatible = "elan,ektf3624", .data = (void *)EKTF3624 },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, elants_of_match);