MIPS: Octeon: Determine if helper needs to be built

This patch adds an config switch to determine if we need to build some
workaround helper files.

The staging driver octeon-ethernet references some symbols which are only
built when PCI is enabled. The new config switch enables these symbols in
bothe cases.

Signed-off-by: Andreas Bießmann <biessmann@corscience.de>
To: linux-kernel@vger.kernel.org
Cc: Andreas Bießmann <biessmann@corscience.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1543/


Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>