irqchip/gic-v3: Enable support for SGIs to act as NMIs

maillist inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8PLUM?from=project-issue
CVE: NA
Reference: https://lore.kernel.org/all/20201102161706.xfqdsro7q7k65ybb@gabell/



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Add support to handle SGIs as pseudo NMIs. As SGIs or IPIs default to a
special flow handler: handle_percpu_devid_fasteoi_ipi(), so skip NMI
handler update in case of SGIs.

Also, enable NMI support prior to gic_smp_init() as allocation of SGIs
as IRQs/NMIs happen as part of this routine.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Wei Li <liwei391@huawei.com>
Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com>
Signed-off-by: Liao Chen <liaochen4@huawei.com>