net/mlx5: Add a locked flag to node removal functions

Add a locked flag to the node removal functions to signal if the
parent is already locked from the caller function or not as a pre-step
towards outside lock. Currently always use false with no functional
change.

Signed-off-by: Eli Britstein <elibr@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>