net: bgmac: enable master mode for BCM54210E and B50212E PHYs

There are 4 very similar PHYs:
0x600d84a1: BCM54210E (rev B0)
0x600d84a2: BCM54210E (rev B1)
0x600d84a5: B50212E (rev B0)
0x600d84a6: B50212E (rev B1)
that need setting master mode manually. It's because they run in slave
mode by default with Automatic Slave/Master configuration disabled which
can lead to unreliable connection with massive ping loss.

So far it was reported for a board with BCM47189 SoC and B50212E B1 PHY
connected to the bgmac supported ethernet device. Telling PHY driver to
setup PHY properly solves this issue.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>