net/mlx5: E-Switch, Avoid setup attempt if not being e-switch manager

In smartnic env, the host (PF) driver might not be an e-switch
manager, hence the FW will err on driver attempts to deal with
setting/unsetting the eswitch and as a result the overall setup
of sriov will fail.

Fix that by avoiding the operation if e-switch management is not
allowed for this driver instance. While here, move to use the
correct name for the esw manager capability name.

Fixes: 81848731 ('net/mlx5: E-Switch, Add SR-IOV (FDB) support')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reported-by: Guy Kushnir <guyk@mellanox.com>
Reviewed-by: Eli Cohen <eli@melloanox.com>
Tested-by: Eli Cohen <eli@melloanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>