perf tools: Make sparc64 arch point to sparc

The recent build changes cause perf to not compile for sparc64 since the
arch/sparc64/Build file does not exist:

/home/dahern/kernels/linux.git/tools/build/Makefile.build:40: arch/sparc64/Build: No such file or directory

Fix by converting the sparc64 RAW_ARCH to sparc ARCH -- similar to what
is done for x86_64.
Signed-off-by: David Ahern <david.ahern@oracle.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1424306222-96843-1-git-send-email-david.ahern@oracle.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/config/Makefile.arch

@@ -21,6 +21,10 @@ ifeq ($(RAW_ARCH),x86_64)
   endif
 endif
 
+ifeq ($(RAW_ARCH),sparc64)
+  ARCH ?= sparc
+endif
+
 ARCH ?= $(RAW_ARCH)
 
 LP64 := $(shell echo __LP64__ | ${CC} ${CFLAGS} -E -x c - | tail -n 1)