image_to_vm: Add --board

BUG=chromium:937821
TEST=./image_to_vm.sh

Change-Id: Ie79324cc0cc62afef5bc213d2fceb0287b884252
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/2275151
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Achuith Bhandarkar <achuith@chromium.org>
Commit-Queue: Achuith Bhandarkar <achuith@chromium.org>
diff --git a/image_to_vm.sh b/image_to_vm.sh
index 0611043..3b9a2c9 100755
--- a/image_to_vm.sh
+++ b/image_to_vm.sh
@@ -262,5 +262,5 @@
 echo "Created image at ${FLAGS_to}"
 
 echo "You can start the image with:"
-echo "cros_vm --start --image-path ${FLAGS_to}/${DEFAULT_QEMU_IMAGE}"
-
+echo "cros_vm --start --board ${FLAGS_board} \
+--image-path ${FLAGS_to}/${DEFAULT_QEMU_IMAGE}"