Input: exc3000 - fix firmware version query for device in bootloader

If the device is stuck in bootloader (maybe due to blank or corrupted
application firmware) it won't answer a query for the firmware version.
Fall back to returning the bootloader version in that case.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Link: https://lore.kernel.org/r/20210125182527.1225245-4-l.stach@pengutronix.de


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>