zenfone8: Add vendor_boot to OTA partitions

Change-Id: I146acadcc789658474986e0ebda625fa57743ff8
diff --git a/BoardConfig.mk b/BoardConfig.mk
index 716ecee..2638a9c 100755
--- a/BoardConfig.mk
+++ b/BoardConfig.mk
@@ -35,7 +35,8 @@
     system_ext \
     vbmeta \
     vbmeta_system \
-    vendor
+    vendor \
+    vendor_boot
 
 # Architecture
 TARGET_ARCH := arm64