exynos4210/mct: Avoid infinite loop on non incremental timers

Check for a 0 "distance" value to avoid infinite loop when the
expired FCR timer was not programed with auto-increment.

With this change the behavior is coherent with the same type
of code in the exynos4210_gfrc_restart() function in the same
file.

Linux seems to mostly use this timer with auto-increment
which explain why it is not a problem most of the time.

However other OS might have a problem with this if they
don't use the auto-increment feature.

Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net>
Reviewed-by: Evgeny Voevodin <e.voevodin@samsung.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
