sw64: add regs and stack access APIs to support kprobe events

Sunway inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I56X48



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To enable kprobes-based dynamic events, we implement the APIs
needed to access registers and stack entries from pt_regs, then
select HAVE_REGS_AND_STACK_ACCESS_API by default.

Signed-off-by: He Chuyue <hechuyue@wxiat.com>

Signed-off-by: Gu Zitao <guzitao@wxiat.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>