clocksource/drivers/arm_arch_timer: Fix handling of ARM erratum 858921

The commit a38b71b0 ("clocksource/drivers/arm_arch_timer:
Move system register timer programming over to CVAL") moves the
programming of the timers from the countdown timer (TVAL) over
to the comparator (CVAL). This makes it necessary to read the
counter when programming next event. However, the workaround of
Cortex-A73 erratum 858921 does not set the corresponding
set_next_event_phys and set_next_event_virt.

Add the appropriate hooks to apply the erratum mitigation when
programming the next timer event.

Fixes: a38b71b0 ("clocksource/drivers/arm_arch_timer: Move system register timer programming over to CVAL")
Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20220914061424.1260-1-jiangkunkun@huawei.com


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>