Input: davinci-keyscan - remove leftover header

The corresponding driver was removed two years ago but the platform data
header was left behind. Remove it now.

Fixes: 3c9cb34 ("input: remove davinci keyboard driver")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20241216083218.22926-1-brgl@bgdev.pl
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: Bartosz Golaszewski