clocksource/drivers/tegra: Cycles can't be 0

Tegra's timer uses n+1 scheme for the counter, i.e. timer will fire after
one tick if 0 is loaded. The minimum and maximum numbers of oneshot ticks
are defined by clockevents_config_and_register(min, max) invocation and
the min value is set to 1 tick. Hence "cycles" value can't ever be 0,
unless it's a bug in clocksource core.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>