qm: fix packet loss for acc

driver inclusion
category: bugfix
bugzilla: NA
CVE: NA

In this patch, we try to change depth of qm_get_avail_sqe.
For hardware qm, 1023 sqe is full. When sqe reaches 1024, qm sqe
tail equal to head, which will be treated as empty queue, causing
packet loss.

Signed-off-by: Yu'an Wang <wangyuan46@huawei.com>
Reviewed-by: Mingqiang Ling <lingmingqiang@huawei.com>
Reviewed-by: Guangwei Zhou <zhouguangwei5@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>