MIPS: BMIPS: Add SMP support code for BMIPS43xx/BMIPS5000

Initial commit of BMIPS SMP support code.  Smoke-tested on a variety of
BMIPS4350, BMIPS4380, and BMIPS5000 platforms.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2977/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index e7587ac..9c4a610 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1986,6 +1986,9 @@
 config CPU_HAS_WB
 	bool
 
+config XKS01
+	bool
+
 #
 # Vectored interrupt mode is an R2 feature
 #