leds: is31fl32xx: define complete i2c_device_id table

Otherwise the driver module will not be automatically probed.

Fixes: 9d7cffaf ("leds: Add driver for the ISSI IS31FL32xx family of LED controllers")
Fixes: e0442d7d

 ("leds: Add SN3218 and SN3216 support to the IS31FL32XX driver")
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Tested-by: David Rivshin <drivshin@allworx.com>
Acked-by: David Rivshin <drivshin@allworx.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>