MIPS: add tune for MIPS 34kc

Add tune Kconfig option for MIPS 34kc.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 0b5dbb6..efe7e44 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -34,6 +34,7 @@
 tune-$(CONFIG_MIPS_TUNE_4KC) += -mtune=4kc
 tune-$(CONFIG_MIPS_TUNE_14KC) += -mtune=14kc
 tune-$(CONFIG_MIPS_TUNE_24KC) += -mtune=24kc
+tune-$(CONFIG_MIPS_TUNE_34KC) += -mtune=34kc
 tune-$(CONFIG_MIPS_TUNE_74KC) += -mtune=74kc
 
 # Include default header files