Use arch-specific flags.

To fix multilib build.

Change-Id: Ifaaea96662de6d3d96a3448754dfe720c4e60deb
diff --git a/cpu_ref/Android.mk b/cpu_ref/Android.mk
index ddc77f2..df9ac09 100644
--- a/cpu_ref/Android.mk
+++ b/cpu_ref/Android.mk
@@ -32,27 +32,25 @@
 	rsCpuIntrinsicLUT.cpp \
 	rsCpuIntrinsicYuvToRGB.cpp
 
-ifeq ($(TARGET_ARCH),arm64)
-    LOCAL_CFLAGS += -DARCH_ARM_HAVE_NEON
-    LOCAL_SRC_FILES+= \
-        rsCpuIntrinsics_advsimd_Blend.S \
-        rsCpuIntrinsics_advsimd_Blur.S \
-        rsCpuIntrinsics_advsimd_YuvToRGB.S
-else
-    ifeq ($(ARCH_ARM_HAVE_NEON),true)
-        LOCAL_CFLAGS += -DARCH_ARM_HAVE_NEON
-    endif
+LOCAL_CFLAGS_arm64 += -DARCH_ARM_HAVE_NEON
+LOCAL_SRC_FILES_arm64 += \
+    rsCpuIntrinsics_advsimd_Blend.S \
+    rsCpuIntrinsics_advsimd_Blur.S \
+    rsCpuIntrinsics_advsimd_YuvToRGB.S
 
-    ifeq ($(ARCH_ARM_HAVE_VFP),true)
-        LOCAL_CFLAGS += -DARCH_ARM_HAVE_VFP
-        LOCAL_SRC_FILES+= \
-            rsCpuIntrinsics_neon.S \
-            rsCpuIntrinsics_neon_ColorMatrix.S \
-            rsCpuIntrinsics_neon_Blend.S \
-            rsCpuIntrinsics_neon_Blur.S \
-            rsCpuIntrinsics_neon_YuvToRGB.S
-        LOCAL_ASFLAGS := -mfpu=neon
-    endif
+ifeq ($(ARCH_ARM_HAVE_NEON),true)
+    LOCAL_CFLAGS_arm += -DARCH_ARM_HAVE_NEON
+endif
+
+ifeq ($(ARCH_ARM_HAVE_VFP),true)
+    LOCAL_CFLAGS_arm += -DARCH_ARM_HAVE_VFP
+    LOCAL_SRC_FILES_arm += \
+    rsCpuIntrinsics_neon.S \
+    rsCpuIntrinsics_neon_ColorMatrix.S \
+    rsCpuIntrinsics_neon_Blend.S \
+    rsCpuIntrinsics_neon_Blur.S \
+    rsCpuIntrinsics_neon_YuvToRGB.S
+    LOCAL_ASFLAGS_arm := -mfpu=neon
 endif
 
 LOCAL_SHARED_LIBRARIES += libRS libcutils libutils liblog libsync