MIPS: PNX8550: 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 6f007c3..ea3b96c 100644
--- a/arch/mips/Kbuild.platforms
+++ b/arch/mips/Kbuild.platforms
@@ -15,6 +15,7 @@
 platforms += mti-malta
 platforms += pmc-sierra
 platforms += pnx833x
+platforms += pnx8550
 platforms += powertv
 platforms += rb532
 platforms += sgi-ip22