Input: atmel_mxt_ts - remove matrix size check

The mxt_check_matrix_size() is currently setting the CTE mode to match
xline/yline information that is in the platform data, but it does not
take into account for example the fact that we could have a key array
in use too (key array would use some x/y lines as well).

It would be better to simply rely on the configuration data, and make
sure that the CTE mode set in there matches the touch object (touchscreen,
key array, proximity) configuration (which are set in the config data too).

Signed-off-by: Iiro Valkonen <iiro.valkonen@atmel.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>