Load CPU device boot loader during driver boot time in order to avoid flash
write for every boot loader update.

To preserve backward-compatibility, skip the device boot load if the device
doesn't request it.
Signed-off-by: Ofir Bitton <obitton@habana.ai>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>