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>
diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
index 094c17e..47323ca 100644
--- a/arch/mips/cavium-octeon/Kconfig
+++ b/arch/mips/cavium-octeon/Kconfig
@@ -83,3 +83,7 @@
 	def_bool y
 	select SPARSEMEM_STATIC
 	depends on CPU_CAVIUM_OCTEON
+
+config CAVIUM_OCTEON_HELPER
+	def_bool y
+	depends on OCTEON_ETHERNET || PCI