RDMA/hns:remove useless header in cmd

driver inclusion
category: cleanup
bugzilla: NA
CVE: NA

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There is a useless header in hns_roce_cmd.c.Remove it.
There is missing space in hns_roce_hw_v2.h and rdfx_common.h.

Reviewed-by: Hu Chunzhi <huchunzhi@huawei.com>
Signed-off-by: Zhao Weibo <zhaoweibo3@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>