clocksource/drivers/arm_arch_timer: Move MMIO timer programming over to CVAL

mainline inclusion
from mainline-v5.16-rc1
commit 8b82c4f8
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4QCBG


CVE: NA

----------------------

Similarily to the sysreg-based timer, move the MMIO over to using
the CVAL registers instead of TVAL. Note that there is no warranty
that the 64bit MMIO access will be atomic, but the timer is always
disabled at the point where we program CVAL.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-8-maz@kernel.org


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>