[media] media: i2c: ths7303: remove unused member driver_data

[media] media: i2c: ths7303: remove unused member driver_data

This patch removes the driver_data member from ths7303_state structure.
The driver_data member was intended to differentiate between ths7303 and
ths7353 chip and get the g_chip_ident, But as of now g_chip_ident is
obsolete, so there is no need of driver_data.

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>