sfc: set the MAC address using MC_CMD_VADAPTOR_SET_MAC

Add a set_mac_address() NIC-type function for EF10 only, and
use this to set the MAC address on the vadaptor. For Siena and
earlier, the MAC address continues to be set by MC_CMD_SET_MAC;
this is still called on EF10, and including a MAC address in
this command has no effect.

The sriov_mac_address_changed() NIC-type function is no longer
needed on EF10, but it is needed for Siena where it is used to
update the peer address of the PF for VFDI.  Change this to use
the new set_mac_address function pointer.

efx_ef10_sriov_mac_address_changed() is no longer called, as VFs
will try to change the MAC address on their vadaptor rather than
trying to change to the context of the PF to alter the vport.

When a VF is running in direct passthrough mode with MAC spoofing
enabled, it will be able to change the MAC address on its vadaptor.
In this case, there is a link to the PF, so find the correct VF in
its ef10_vf array and update the MAC address.

ndo_set_mac_address() can be called during driver unload while
bonding, and in this case the device has already been stopped, so
don't call efx_net_open() to restart it after reconfiguration.

efx->port_enabled is set to false in efx_stop_port(), so it is
indicator of whether the device needs to be restarted.

Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>