tools build: Add test for sched_getcpu()

Instead of trying to go on adding more ifdef conditions, do a feature
test and define HAVE_SCHED_GETCPU_SUPPORT instead, then use it to
provide the prototype. No need to change the stub, as it is already a
__weak symbol.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-yge89er9g90sc0v6k0a0r5tr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/build/Makefile.feature b/tools/build/Makefile.feature
index e3fb5ecb..523911f 100644
--- a/tools/build/Makefile.feature
+++ b/tools/build/Makefile.feature
@@ -63,6 +63,7 @@
         lzma                            \
         get_cpuid                       \
         bpf                             \
+        sched_getcpu			\
         sdt
 
 # FEATURE_TESTS_BASIC + FEATURE_TESTS_EXTRA is the complete list