Input: remove CLOCK_TICK_RATE from analog joystick driver

The analog joystick driver is written for x86 systems. This
patch updates it to use the PIT_TICK_RATE value instead of
CLOCK_TICK_RATE as they are equivalent on x86 and we want to
deprecate the latter.

Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>