Input: Kconfig: remove dependency for atmel_tsadcc driver

This will allow to select this driver for newer SoCs.
Keep dependency on AT91 because of the use of an header
file located in include/mach directory.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Dmitry Torokhov <dtor@mail.ru>