net/mlx5: Fix required capability for manipulating MPFS

[ Upstream commit f811980444ec59ad62f9e041adbb576a821132c7 ]

Manipulating of the MPFS requires eswitch manager capabilities.

Fixes: eeb66cdb ('net/mlx5: Separate between E-Switch and MPFS')
Signed-off-by: Eli Cohen <eli@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>