net: atlantic: possible fault in transition to hibernation

during hibernation freeze, aq_nic_stop could be invoked
on a stopped device. That may cause panic on access to
not yet allocated vector/ring structures.

Add a check to stop device if it is not yet stopped.

Similiarly after freeze in hibernation thaw, aq_nic_start
could be invoked on a not initialized net device.
Result will be the same.

Add a check to start device if it is initialized.
In our case, this is the same as started.

Fixes: 8aaa112a ("net: atlantic: refactoring pm logic")
Signed-off-by: Pavel Belous <pbelous@marvell.com>
Signed-off-by: Nikita Danilov <ndanilov@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Dmitry Bogdanov <dbogdanov@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>