net: phy: bcm7xxx: re-advertise all supported modes out of suspend

The BCM7xxx internal Gigabit PHYs on 28nm process platforms come out
reset without any half-duplex or "hub" compatible advertised modes,
which was causing auto-negotiation issues coming out of S3
suspend/resume, we just could not establish a link with a half-duplex
only link partner.

Make sure that the resume function properly re-configures the PHY device
to advertise all supported modes.

Fixes: b560a58c

 ("net: phy: add Broadcom BCM7xxx internal PHY driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@greenl8ke.davemloft.net>