update_bootloaders: Remove board_specific_setup hook

No boards define a board_update_bootloaders function.  Take this hook
away before people start using it.

BUG=none
TEST=CQ

Change-Id: Ib4f78bd81e2b8eb2fb404176c4c7fb89e8ebda5a
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/4864969
Reviewed-by: Greg Edelston <gredelston@google.com>
Tested-by: Jack Rosenthal <jrosenth@chromium.org>
Auto-Submit: Jack Rosenthal <jrosenth@chromium.org>
Commit-Queue: Greg Edelston <gredelston@google.com>
diff --git a/update_bootloaders.sh b/update_bootloaders.sh
index 282b326..af5b97f 100755
--- a/update_bootloaders.sh
+++ b/update_bootloaders.sh
@@ -64,7 +64,6 @@
 
 # shellcheck source=build_library/board_options.sh
 . "${BUILD_LIBRARY_DIR}/board_options.sh" || exit 1
-load_board_specific_script "board_specific_setup.sh"
 
 part_index_to_uuid() {
   local image="$1"
@@ -229,8 +228,4 @@
   fi
 fi
 
-if type board_update_bootloaders >&/dev/null; then
-  board_update_bootloaders "${BOARD_ROOT}" "${ESP_FS_DIR}"
-fi
-
 set +e