RDMA/rtrs: Clean up rtrs_rdma_dev_pd_ops

Let's remove them since the three members are not used.

Acked-by: Md Haris Iqbal <haris.iqbal@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20221117101945.6317-7-guoqing.jiang@linux.dev


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