IB/mlx5: Fix obj_type mismatch for SRQ event subscriptions

IB/mlx5: Fix obj_type mismatch for SRQ event subscriptions

Fix a bug where the driver's event subscription logic for SRQ-related
events incorrectly sets obj_type for RMP objects.

When subscribing to SRQ events, get_legacy_obj_type() did not handle
the MLX5_CMD_OP_CREATE_RMP case, which caused obj_type to be 0
(default).
This led to a mismatch between the obj_type used during subscription
(0) and the value used during notification (1, taken from the event's
type field). As a result, event mapping for SRQ objects could fail and
event notification would not be delivered correctly.

This fix adds handling for MLX5_CMD_OP_CREATE_RMP in get_legacy_obj_type,
returning MLX5_EVENT_QUEUE_TYPE_RQ so obj_type is consistent between
subscription and notification.

Fixes: 759738537142 ("IB/mlx5: Enable subscription for device events over DEVX")
Link: https://patch.msgid.link/r/8f1048e3fdd1fde6b90607ce0ed251afaf8a148c.1755088962.git.leon@kernel.org
Signed-off-by: Or Har-Toov <ohartoov@nvidia.com>
Reviewed-by: Edward Srouji <edwards@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>