clocksource/drivers/timer-gx6605s: Fixup counter reload

When the timer counts to the upper limit, an overflow interrupt is
generated, and the count is reset with the value in the TIME_INI
register. But the software expects to start counting from 0 when
the count overflows, so it forces TIME_INI to 0 to solve the
potential interrupt storm problem.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Tested-by: Xu Kai <xukai@nationalchip.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1597735877-71115-1-git-send-email-guoren@kernel.org