media: v4l2: Correct kernel-doc inconsistency

Silence documentation build warnings by correcting kernel-doc comment
v4l2_subdev_get_fwnode_pad_1_to_1 function

./include/media/v4l2-subdev.h:1045: warning: Function parameter or member 'entity' not described in 'v4l2_subdev_get_fwnode_pad_1_to_1'
./include/media/v4l2-subdev.h:1045: warning: Function parameter or member 'endpoint' not described in 'v4l2_subdev_get_fwnode_pad_1_to_1'

Signed-off-by: Colton Lewis <colton.w.lewis@protonmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>