qed: Fix setting of incorrect eswitch mode.

By default, driver sets the eswitch mode incorrectly as VEB (virtual
Ethernet bridging).
Need to set VEB eswitch mode only when sriov is enabled, and it should be
to set NONE by default. The patch incorporates this change.

Fixes: 0fefbfba

 ("qed*: Management firmware - notifications and defaults")
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Michal Kalderon <Michal.Kalderon@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>