staging: ks7010: use msecs_to_jiffies in ks7010_rw_function function

This commit replaces custom time calculations done in ks7010_rw_function
with msecs_to_jiffies() function which has the same behaviour.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>