Move original tumbl firmware out of way of new one.

Signed-off-by: Pavel Pisa <ppisa@pikron.com>

diff --git a/hw/lx-rocon_firmware/firmware.c b/hw/lx-rocon_firmware/fw_test.c
similarity index 100%
rename from hw/lx-rocon_firmware/firmware.c
rename to hw/lx-rocon_firmware/fw_test.c