hwmon: (nzxt-smart2) Add support for another version of NZXT RGB & Fan Controller

Add support for NZXT RGB & Fan Controller with USB ID 1e71:2020.

Fan speed control reported to be working with existing userspace (hidraw)
software, so it should be compatible. Fan channel count is the same.
No known differences from already supported devices, at least regarding
fan speed control and initialization.

Signed-off-by: Aleksandr Mezin <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
[groeck: Adjusted subject and description]
Signed-off-by: Guenter Roeck <[e-mail]>

drivers/hwmon/nzxt-smart2.c

···
 	{ HID_USB_DEVICE(0x1e71, 0x2010) }, /* NZXT RGB & Fan Controller */
 	{ HID_USB_DEVICE(0x1e71, 0x2011) }, /* NZXT RGB & Fan Controller (6 RGB) */
 	{ HID_USB_DEVICE(0x1e71, 0x2019) }, /* NZXT RGB & Fan Controller (6 RGB) */
+	{ HID_USB_DEVICE(0x1e71, 0x2020) }, /* NZXT RGB & Fan Controller (6 RGB) */
 	{},
 };