DP83620 register set is compatible with the DP83848, but it also supports
100base-FX. When the hardware is configured such as that fiber mode is
enabled, autonegotiation is not possible.

The chip, however, doesn't expose this information via BMSR_ANEGCAPABLE.
Instead, this bit is always set high, even if the particular hardware
configuration makes it so that auto negotiation is not possible [1]. Under
these circumstances, the phy subsystem keeps trying for autonegotiation to
happen, without success.

Hereby, we inspect BMCR_ANENABLE bit after genphy_config_init, which on
reset is set to 0 when auto negotiation is disabled, and so we use this
value instead of BMSR_ANEGCAPABLE.

[1] https://e2e.ti.com/support/interface/ethernet/f/903/p/697165/2571170Signed-off-by: NAlvaro Gamez Machado <alvaro.gamez@hazent.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>