ipmi_si: ls2k500 kcs driver add wait bmc reboot done and rebind support.

LoongArch inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7CPCD



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Signed-off-by: Chong Qiao <qiaochong@loongson.cn>
Signed-off-by: Hongchen Zhang <zhanghongchen@loongson.cn>