Input: wdt87xx_i2c - change the sleep time to 2500ms after the sw reset

The original wait time was 200ms which was enough for the firmware to
finish loading and boot. After that the firmware will perform
initialization and touch calibration, which will take about 1.1 second. The
touch calibration will change controller frequency to scan at the most
optimal frequency and during calibration/frequency switching process we may
run into i2c data errors. To avoid them we extend the sleep to 2500ms after
issuing the sw reset.

Signed-off-by: HungNien Chen <hn.chen@weidahitech.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>