Input: iqs5xx - drop unused i2c driver_data

The driver doesn't make use of the value that was explicitly assigned to
the .driver_data members. Drop the assignment. While touching the array,
convert it to use named initialization which is easier to understand.

Signed-off-by: Uwe Kleine-König (The Capable Hub) <u.kleine-koenig@baylibre.com>
Link: https://patch.msgid.link/20260515165135.498505-2-u.kleine-koenig@baylibre.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>