Add initial dummy file to allow testing the ebuild

BUG=b:192528245
TEST=emerge-grunt chromeos-firmware-hps

Change-Id: Icde0de49fe19450e42c2dd18f67ef8826c329dee
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/hps-firmware-images/+/3010790
Tested-by: Evan Benn <evanbenn@chromium.org>
Auto-Submit: Evan Benn <evanbenn@chromium.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
Commit-Queue: Edward O'Callaghan <quasisec@chromium.org>
diff --git a/firmware-bin/hps.bin b/firmware-bin/hps.bin
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/firmware-bin/hps.bin