MIPS: Changes to configuration files for SEAD-3 platform.

Change MIPS configuration files to add the SEAD-3. Also add
new default configuration file for a SEAD-3 kernel.

Signed-off-by: Steven J. Hill <sjhill@mips.com>
diff --git a/arch/mips/Kbuild.platforms b/arch/mips/Kbuild.platforms
index d64786d..98d1e3c 100644
--- a/arch/mips/Kbuild.platforms
+++ b/arch/mips/Kbuild.platforms
@@ -17,6 +17,7 @@
 platforms += loongson1
 platforms += mipssim
 platforms += mti-malta
+platforms += mti-sead3
 platforms += netlogic
 platforms += pmc-sierra
 platforms += pnx833x