[PATCH] perf: bpf: Fix build breakage due to libbpf

["Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>]

perf build is currently (v4.4-rc5) broken on powerpc:

bpf.c:28:4: error: #error __NR_bpf not defined. libbpf does not support
your arch.
 #  error __NR_bpf not defined. libbpf does not support your arch.
    ^

Fix this by including tools/perf/config/Makefile.arch for the proper
$ARCH macro. While at it, remove redundant LP64 macro definition.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
 tools/lib/bpf/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 636e3dd..050e0e8 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -31,7 +31,8 @@ INSTALL = install
 DESTDIR ?=
 DESTDIR_SQ = '$(subst ','\'',$(DESTDIR))'
 
-LP64 := $(shell echo __LP64__ | ${CC} ${CFLAGS} -E -x c - | tail -n 1)
+include $(srctree)/tools/perf/config/Makefile.arch
+
 ifeq ($(LP64), 1)
   libdir_relative = lib64
 else
-- 
2.6.2