livepatch/ppc64: only check stack top

hulk inclusion
category: feature
bugzilla: 119440 https://gitee.com/openeuler/kernel/issues/I4DDEL



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Enable stack optimize on ppc64.

Signed-off-by: Ye Weihua <yeweihua4@huawei.com>
Reviewed-by: Kuohai Xu <xukuohai@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>