MIPS: Octeon: Migrate to new platform makefile style.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kbuild.platforms b/arch/mips/Kbuild.platforms
index c00aa34..5a45333 100644
--- a/arch/mips/Kbuild.platforms
+++ b/arch/mips/Kbuild.platforms
@@ -4,6 +4,7 @@
 platforms += ar7
 platforms += bcm47xx
 platforms += bcm63xx
+platforms += cavium-octeon
 platforms += cobalt
 platforms += dec
 platforms += jazz