net/mlx5: Fix arm SRQ command for ISSI version 0

Support for ISSI version 0 was recently broken as the arm_srq_cmd
command, which is used only for ISSI version 0, was given the opcode
for ISSI version 1 instead of ISSI version 0.

Change arm_srq_cmd to use the correct command opcode for ISSI version
0.

Fixes: af1ba291 ('{net, IB}/mlx5: Refactor internal SRQ API')
Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>