target.mk: Remove obsolete octeon CPU_CFLAGS

As of commit c6e02b49f6 the octeon target
uses octeonplus instead of octeon

Signed-off-by: Daniel Engberg <daniel.engberg.lists@pyret.net>

include/target.mk

@@ -174,7 +174,6 @@ ifeq ($(DUMP),1)
     CPU_CFLAGS_mips64 = -mips64 -mtune=mips64 -mabi=64
     CPU_CFLAGS_24kc = -mips32r2 -mtune=24kc
     CPU_CFLAGS_74kc = -mips32r2 -mtune=74kc
-    CPU_CFLAGS_octeon = -march=octeon -mabi=64
     CPU_CFLAGS_octeonplus = -march=octeon+ -mabi=64
   endif
   ifeq ($(ARCH),i386)