Input: joystick - use get_cycles on ARMv8

As with ARM the ARMv8 architecture provides a cycle counter which can be
used to provide a high resolution time for the joystick driver and
silence the build warning that results from not having a precise timer
on ARMv8, making allmodconfig and allyesconfig quieter.

Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>