EMMC: fix ascend hisi emmc probe failed problem according to mmc_host struct

ascend inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4GVSG


CVE: NA

-------------------

Struct mmc_host using variable private[0] to point the end of struct
mmc_host, at deaf01a6 we modified struct mmc_host but ignored the
role of private[0] and not put it to the end of struct mmc_host.

It will make mmc card probe failed, so we fix this problem, and now
ascend hisi mmc card is able to probe success.

Signed-off-by: zhangguijiang <zhangguijiang@huawei.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>