arm64: kexec: only clear EOI for SDEI in NMI context

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8LQCC


CVE: NA

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We need to clear EOI for the secure timer only when we panic from
sdei_handler. If we clear EOI for the secure timer in normal panic
routiue, it has no bad effect on Hi1620, but it may cause undefine
behavior on Hi1616. So add a check for NMI context before we clear EOI
for the secure timer.

Fixes: dd397d5febc4("sdei_watchdog: clear EOI of the secure timer before
kdump")

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>
Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com>