perf has same dwarf-regs for x86 and x86_64

Change-Id: I155981fe4373468cccfbff6b78e98c7db555275c
Signed-off-by: Fengwei Yin <fengwei.yin@intel.com>
diff --git a/perf-3.12.0/tools/perf/Android.mk b/perf-3.12.0/tools/perf/Android.mk
index ae9bfd3..794e3bf 100644
--- a/perf-3.12.0/tools/perf/Android.mk
+++ b/perf-3.12.0/tools/perf/Android.mk
@@ -24,12 +24,17 @@
 
 ifdef cur_platform
 
+perf_arch := $(TARGET_ARCH)
+ifeq ($(TARGET_ARCH), x86_64)
+perf_arch := x86
+endif
+
 #
 # target libperf
 #
 libperf_src_files := \
 	arch/common.c \
-	arch/$(TARGET_ARCH)/util/dwarf-regs.c \
+	arch/$(perf_arch)/util/dwarf-regs.c \
 	tests/attr.c \
 	ui/helpline.c \
 	ui/hist.c \