Add TARGET_CPU_VARIANT of cortex-a15 for arndale.

Bug: 8005082

Merge from internal master.

Change-Id: I1fbb02e6d2aebee8a0c62ce25d33e4f79f0851fe
diff --git a/BoardConfig.mk b/BoardConfig.mk
index bbbf7a8..1c6ebba 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -19,5 +19,6 @@
 
 TARGET_ARCH := arm
 TARGET_ARCH_VARIANT := armv7-a-neon
+TARGET_CPU_VARIANT := cortex-a15
 TARGET_CPU_ABI := armeabi-v7a
 TARGET_CPU_ABI2 := armeabi