Use ARCH_ARM_HAVE_ARMV7A to select qemu kernel for dexpreopt

Change-Id: I440d944e87324038e465415b1b71613b31052f99
diff --git a/tools/dexpreopt/Config.mk b/tools/dexpreopt/Config.mk
index 443b8c9..b2b32c6 100644
--- a/tools/dexpreopt/Config.mk
+++ b/tools/dexpreopt/Config.mk
@@ -78,7 +78,7 @@
 endif
 
 # The kernel used for ARMv7 system images is different
-ifeq ($(TARGET_ARCH_VARIANT),armv7-a)
+ifeq ($(ARCH_ARM_HAVE_ARMV7A),true)
 BUILD_DEXPREOPT_KERNEL := prebuilt/android-arm/kernel/kernel-qemu-armv7
 else
 BUILD_DEXPREOPT_KERNEL := prebuilt/android-arm/kernel/kernel-qemu