ARM: Kirkwood: Remove mach-kirkwood

Now that all boards have been converted to DT and all the support code
lives in mach-mvebu, we can remove mach-kirkwood.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lkml.kernel.org/r/1405028192-9623-2-git-send-email-andrew@lunn.ch


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