media: v4l: uAPI: V4L2_BUF_TYPE_META_OUTPUT is an output buffer type

V4L2_BUF_TYPE_META_OUTPUT was added by commit 72148d1a
("media: v4l: Add support for V4L2_BUF_TYPE_META_OUTPUT") but the patch
missed adding the type to the macro telling whether a given type is an
output type or not. Do that now. Getting this wrong leads to handling the
buffer as a capture buffer in a lot of places.

Fixes: 72148d1a ("media: v4l: Add support for V4L2_BUF_TYPE_META_OUTPUT")

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>