ARM: socfpga: PM: add missing put_device() call in socfpga_setup_ocram_self_refresh()

if of_find_device_by_node() succeed, socfpga_setup_ocram_self_refresh
doesn't have a corresponding put_device(). Thus add a jump target to
fix the exception handling for this function implementation.

Fixes: 44fd8c7d ("ARM: socfpga: support suspend to ram")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>