MIPS: introduce CPU_R4K_CACHE_TLB

R4K-style CPUs having common code to support their caches and tlb have this
boolean defined by default. Allows us to remove some lines in
arch/mips/mm/Makefile.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/3328/
Signed-off-by: John Crispin <blogic@openwrt.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 0920936f..1dcbbd1 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1888,6 +1888,10 @@
 	bool
 	default y if !(CPU_R3000 || CPU_R6000 || CPU_TX39XX || CPU_CAVIUM_OCTEON)
 
+config CPU_R4K_CACHE_TLB
+	bool
+	default y if !(CPU_R3000 || CPU_R8000 || CPU_SB1 || CPU_TX39XX || CPU_CAVIUM_OCTEON)
+
 choice
 	prompt "MIPS MT options"