don't call blobutil directly from lbmk

it's bloat, and was only there for backwards compatibility
with the old commands, but the new commands are e.g.

./update blobs inject

instead of:

./blobutil inject

this results in a slight code size reduction in lbmk

Signed-off-by: Leah Rowe <leah@libreboot.org>

resources/scripts/build/boot/roms

@@ -131,7 +131,7 @@ buildrom() {
 
 	# Start by building blobs and placing them in the
 	# coreboot tree only for boards that need them
-	./blobutil download ${board} || exit 1
+	./update blobs download ${board} || exit 1
 
 	if [ -d "resources/coreboot/${board}/" ]; then
 		./build boot roms_helper ${board}${opts}