Input: joystick - use ktime for measuring timing

The current codes in gameport and analog joystick drivers for the time
accounting have a long-standing problem when the system is running
with CPU freq; since the timing is measured via TSC or sample counter,
the calculation isn't reliable.

In this patch, as a simple fix, use the standard ktime to measure the
timing.  In case where no high resolution timer is available,
use_ktime bool option is provided to both modules.  Setting
use_ktime=false switches to the old methods.

Tested-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>