Removing the phy_stop() from bcmgenet_netif_stop() ended up causing
warnings from the PHY library that phy_start() is called from the
RUNNING state since we are no longer stopping the PHY state machine.
Restore the call to phy_stop() but make it conditional on being called
fro the close or suspend path.
Fixes: 93e0401e0fc0 ("net: bcmgenet: Remove phy_stop() from bcmgenet_netif_stop()")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>