Input: elan_i2c - add support for ELAN0621 touchpad

Added the ability to detect the ELAN0621 touchpad found in some Lenovo
laptops.

Signed-off-by: Adam Wong <adam@adamwong.me>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/elan_i2c_core.c

@@ -1349,6 +1349,7 @@ static const struct acpi_device_id elan_acpi_id[] = {
 	{ "ELAN061C", 0 },
 	{ "ELAN061D", 0 },
 	{ "ELAN0620", 0 },
+	{ "ELAN0621", 0 },
 	{ "ELAN0622", 0 },
 	{ "ELAN1000", 0 },
 	{ }