accel/habanalabs: add fw status SHUTDOWN_PREP

update hl_boot_if.h from specs to include
CPU_BOOT_STATUS_FW_SHUTDOWN_PREP

Signed-off-by: Dafna Hirschfeld <dhirschfeld@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>