MIPS: introduce CPU_R4K_FPU

R4K-style CPUs have this boolean defined by default. Allows us
to remove some lines in arch/mips/kernel/Makefile.

Signed-off-by: Florian Fainelli <florian@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/3330/
Signed-off-by: John Crispin <blogic@openwrt.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index b805ccd..0920936f 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1884,6 +1884,10 @@
 	bool
 	default y if !(CPU_R3000 || CPU_R6000 || CPU_R8000 || CPU_TX39XX)
 
+config CPU_R4K_FPU
+	bool
+	default y if !(CPU_R3000 || CPU_R6000 || CPU_TX39XX || CPU_CAVIUM_OCTEON)
+
 choice
 	prompt "MIPS MT options"