zenfone6.: Set HASHTREE_DISABLED for avb

Change-Id: I0e28d7a55f4db61627d2d11281d6c139aca20321
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 952dca7..276769f 100755
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -48,6 +48,7 @@
 
 # A/B
 BOARD_AVB_ENABLE := true
+BOARD_AVB_MAKE_VBMETA_IMAGE_ARGS += --set_hashtree_disabled_flag
 BOARD_AVB_MAKE_VBMETA_IMAGE_ARGS += --flags 2
 
 # ANT+