mlx4: Avoid resetting MLX4_INTFF_BONDING per driver

The mlx4_core driver has a logic that allows a sub-driver to set the
MLX4_INTFF_BONDING flag which then causes that function mlx4_do_bond()
asks the sub-driver to fully re-probe a device when its bonding
configuration changes.

Performing this operation is disallowed in mlx4_register_interface()
when it is detected that any mlx4 device is multifunction (SRIOV). The
code then resets MLX4_INTFF_BONDING in the driver flags.

Move this check directly into mlx4_do_bond(). It provides a better
separation as mlx4_core no longer directly modifies the sub-driver flags
and it will allow to get rid of explicitly keeping track of all mlx4
devices by the intf.c code when it is switched to an auxiliary bus.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Tested-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>