Adding TARGET_CPU_VARIANT to config file.

Merge from internal master.

Change-Id: Id485e35d6b0288a95e9cdf7314b0d026d66253f9
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 4211588..88137d6 100644
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -31,6 +31,7 @@
 TARGET_CPU_SMP := true
 TARGET_ARCH:= arm
 TARGET_ARCH_VARIANT := armv7-a-neon
+TARGET_CPU_VARIANT := cortex-a9
 ARCH_ARM_HAVE_TLS_REGISTER := true
 
 BOARD_HAVE_BLUETOOTH := true