share_pool: Make multi-device support extendable

ascend inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SON8


CVE: NA

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The maximum devices supported in share_pool in static. Here we make it
extendable for later use.

Signed-off-by: Wang Wensheng <wangwensheng4@huawei.com>
Reviewed-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>