RDMA/hns: Remove the num_qpc_timer variable

RDMA/hns: Remove the num_qpc_timer variable

The bt number of qpc_timer of HIP09 increases compared with that of HIP08.
Therefore, qpc_timer_bt_num and num_qpc_timer do not match. As a result,
the driver may fail to allocate qpc_timer. So the driver needs to uniquely
uses qpc_timer_bt_num to represent the bt number of qpc_timer.

Fixes: 0e40dc2f70cd ("RDMA/hns: Add timer allocation support for hip08")
Link: https://lore.kernel.org/r/20220829105021.1427804-4-liangwenpeng@huawei.com
Signed-off-by: Yixing Liu <liuyixing1@huawei.com>
Signed-off-by: Wenpeng Liang <liangwenpeng@huawei.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>