STAGING: Octeon: Use common helpers for determining interface and port

Currently the Octeon Ethernet driver hardcodes the mapping between
interface/port and IPD port number. Since we have generic helpers for
the very same purpose, we might as well use them instead. This prevents
having the same information in multiple places.

Signed-off-by: Janne Huttunen <janne.huttunen@nokia.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/10975/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>