AVB: support BOARD_BUILD_SYSTEM_ROOT_IMAGE

Passing --setup_rootfs_from_kernel to avbtool when
BOARD_BUILD_SYSTEM_ROOT_IMAGE is true

Bug: 33590159
Test: 'make' sailfish with BOARD_AVB_ENABLE := true
Test: 'make dist' with BOARD_AVB_ENABLE := true
Change-Id: Ieb58dd9ae6be1eceb90a33c739b85cff5cbc6e0a
Merged-In: Ieb58dd9ae6be1eceb90a33c739b85cff5cbc6e0a
(cherry picked from commit 9b3776017f45b9857067929dac35f4e5f8ffdf17)
diff --git a/tools/releasetools/add_img_to_target_files.py b/tools/releasetools/add_img_to_target_files.py
index abdbbbb..7c3679c 100755
--- a/tools/releasetools/add_img_to_target_files.py
+++ b/tools/releasetools/add_img_to_target_files.py
@@ -293,10 +293,11 @@
   cmd = [avbtool, "make_vbmeta_image",
          "--output", img.name,
          "--include_descriptors_from_image", boot_img_path,
-         "--include_descriptors_from_image", system_img_path,
-         "--generate_dm_verity_cmdline_from_hashtree", system_img_path]
+         "--include_descriptors_from_image", system_img_path]
   if vendor_img_path is not None:
     cmd.extend(["--include_descriptors_from_image", vendor_img_path])
+  if OPTIONS.info_dict.get("system_root_image", None) == "true":
+    cmd.extend(["--setup_rootfs_from_kernel", system_img_path])
   common.AppendAVBSigningArgs(cmd)
   args = OPTIONS.info_dict.get("board_avb_make_vbmeta_image_args", None)
   if args and args.strip():