ARM: mvebu: defconfig: Enable the mv88E6171 switch driver

This switch is used by the 370-rd. Enable it and support for
fixed-link phy configuration.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1415214121-29286-4-git-send-email-andrew@lunn.ch


Signed-off-by: Jason Cooper <jason@lakedaemon.net>