target: add cpu flags for powerpc64

Signed-off-by: Florian Larysch <fl@n621.de>

include/target.mk

@@ -205,6 +205,10 @@ ifeq ($(DUMP),1)
     CPU_CFLAGS_440:=-mcpu=440
     CPU_CFLAGS_464fp:=-mcpu=464fp
   endif
+  ifeq ($(ARCH),powerpc64)
+    CPU_TYPE ?= powerpc64
+    CPU_CFLAGS_powerpc64:=-mcpu=powerpc64
+  endif
   ifeq ($(ARCH),sparc)
     CPU_TYPE = sparc
     CPU_CFLAGS_ultrasparc = -mcpu=ultrasparc