RDMA/erdma: Minor refactor of device init flow

After necessary configuration, driver should wait hardware finishing
initialization. The wait sets at CMDQ related function though it has
nothing to do with CMDQ. Refactor this part to make code cleaner.

Signed-off-by: Cheng Xu <chengyou@linux.alibaba.com>
Link: https://lore.kernel.org/r/20230322093319.84045-4-chengyou@linux.alibaba.com


Signed-off-by: Leon Romanovsky <leon@kernel.org>