media: mtk-vcodec: add missing put_device() call in mtk_vcodec_init_enc_pm()

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

Fixes: 4e855a6e ("[media] vcodec: mediatek: Add Mediatek V4L2 Video Encoder Driver")
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>