MIPS: Octeon: Initialize CN68XX PKO

MIPS: Octeon: Initialize CN68XX PKO

CN68XX requires a different PKO configuration. This patch provides
just enough setup to get the XAUI interfaces on CN6880 working with
default parameters.

Signed-off-by: Janne Huttunen <janne.huttunen@nsn.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Acked-by: David Daney <david.daney@cavium.com>
Cc: David Daney <ddaney.cavm@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: Janne Huttunen <janne.huttunen@nokia.com>
Cc: Aaro Koskinen <aaro.koskinen@nokia.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: devel@driverdev.osuosl.org
Patchwork: https://patchwork.linux-mips.org/patch/10974/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>