Input: synaptics - Lenovo Carbon X1 Gen5 (2017) devices should use RMI

The touchpad on Lenovo Carbon X1 Gen 5 (2017 - Kabylake) is accessible over
SMBUS/RMI, so let's activate it by default.

Cc: stable@vger.kernel.org
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/synaptics.c

@@ -172,6 +172,7 @@ static const char * const smbus_pnp_ids[] = {
 	"LEN0048", /* X1 Carbon 3 */
 	"LEN0046", /* X250 */
 	"LEN004a", /* W541 */
+	"LEN0072", /* X1 Carbon Gen 5 (2017) - Elan/ALPS trackpoint */
 	"LEN200f", /* T450s */
 	NULL
 };