media: si2168: add support for Mygica T230C v2

The T230C v2 hardware needs a mode of the si2168 chip to be
set for which the si2168 driver previously had no support.
This patch uses a specific measure to configure this on the
T230C v2 hardware only - see the flag passed via the ts_mode
attribute and its dependency on USB_PID_MYGICA_T230C2.

Signed-off-by: Jan Pieter van Woerkom <jp@jpvw.nl>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>