Fix multi-arch build for x86

atomicops_internals_x86_gcc.cc should be also added to source file
when x86 is built as the 2nd arch

Change-Id: Iad9f6728edb9a1036a0bd52ea1307c7fec20022f
Signed-off-by: Qiming Shi <qiming.shi@intel.com>

Android.mk

diff --git a/Android.mk b/Android.mk
index 275178c..1b31c6f 100644
--- a/Android.mk
+++ b/Android.mk
@@ -51,6 +51,11 @@
     base/atomicops_internals_x86_gcc.cc
 endif
 
+ifeq ($(TARGET_$(combo_2nd_arch_prefix)ARCH),x86)
+LOCAL_SRC_FILES += \
+    base/atomicops_internals_x86_gcc.cc
+endif
+
 LOCAL_SRC_FILES += \
     base/at_exit.cc \
     base/base64.cc \