media: v4l2-ioctl: print capabilities in v4l_print_create_buffers()

Print capabilities field from struct v4l2_create_buffers for better
debugging.

Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>