tools: Move Makefile.arch from perf/config to tools/scripts

After this patch other directories can use this architecture detector
without directly including it from perf's directory. Libbpf would
utilize it to get proper $(ARCH) so it can receive correct uapi include
directory.
Tested-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1452520124-2073-8-git-send-email-wangnan0@huawei.com
[ Add missing srctree definition in tests/make ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@kernel.org>

tools/perf/config/Makefile

@@ -17,7 +17,7 @@ detected_var = $(shell echo "$(1)=$($(1))" >> $(OUTPUT).config-detected)
 
 CFLAGS := $(EXTRA_CFLAGS) $(EXTRA_WARNINGS)
 
-include $(src-perf)/config/Makefile.arch
+include $(srctree)/tools/scripts/Makefile.arch
 
 $(call detected_var,ARCH)
 

tools/perf/tests/make

+include ../scripts/Makefile.include
+
 ifndef MK
 ifeq ($(MAKECMDGOALS),)
 # no target specified, trigger the whole suite
@@ -12,7 +14,19 @@ endif
 else
 PERF := .
 
-include config/Makefile.arch
+# As per kernel Makefile, avoid funny character set dependencies
+unexport LC_ALL
+LC_COLLATE=C
+LC_NUMERIC=C
+export LC_COLLATE LC_NUMERIC
+
+ifeq ($(srctree),)
+srctree := $(patsubst %/,%,$(dir $(shell pwd)))
+srctree := $(patsubst %/,%,$(dir $(srctree)))
+#$(info Determined 'srctree' to be $(srctree))
+endif
+
+include $(srctree)/tools/scripts/Makefile.arch
 
 # FIXME looks like x86 is the only arch running tests ;-)
 # we need some IS_(32/64) flag to make this generic