zenfone7: Build vendor.qti.hardware.vibrator from source

Change-Id: Ie02c835ecc8e94de03fc9810925d06fb84becaa6
diff --git a/device.mk b/device.mk
index cd29191..c4e4414 100755
--- a/device.mk
+++ b/device.mk
@@ -75,6 +75,10 @@
 PRODUCT_SOONG_NAMESPACES += \
     $(LOCAL_PATH)
 
+# Vibrator
+PRODUCT_PACKAGES += \
+    vendor.qti.hardware.vibrator.service
+
 # Inherit from asus sm8250-common
 $(call inherit-product, device/asus/sm8250-common/common.mk)