Input: matrix_keypad - use fsleep for delays after activating columns

Input: matrix_keypad - use fsleep for delays after activating columns

The delay is specified in a device property, so the duration can be
arbitrarily large. fsleep() determines the best way of delaying (sleep
vs spin) based on duration.

see Documentation/timers/delay_sleep_functions.rst

Signed-off-by: Markus Burri <markus.burri@mt.com>
Reviewed-by: Manuel Traut <manuel.traut@mt.com>
Link: https://lore.kernel.org/r/20250110054906.354296-2-markus.burri@mt.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>