tick/nohz: Remove duplicate between lowres and highres handlers

tick_nohz_lowres_handler() does the same work as
tick_nohz_highres_handler() plus the clockevent device reprogramming, so
make the former reuse the latter and rename it accordingly.

Signed-off-by: Peng Liu <liupeng17@lenovo.com>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20240225225508.11587-3-frederic@kernel.org