media: rp1: cfe: Dual purpose video nodes

media: rp1: cfe: Dual purpose video nodes

The RP1 CSI-2 DMA can capture both video and metadata just fine, but at
the moment the video nodes are only set to support either video or
metadata.

Make the changes to support both video and metadata. This mostly means
tracking both video format and metadata format separately for each video
node, and using vb2_queue_change_type() to change the vb2 queue type
when needed.

Briefly, this means that the user can get/set both video and meta
formats to a single video node. The vb2 queue buffer type will be
changed when the user calls REQBUFS or CREATE_BUFS ioctls. This buffer
type will be then used as the "mode" for the video node when the user
starts the streaming, and based on that either the video or the meta
format will be used.

A bunch of macros are added (node_supports_xxx()), which tell if a node
can support a particular mode, whereas the existing macros
(is_xxx_node()) will tell if the node is currently in a particular mode.
Note that the latter will only work correctly between the start of the
streaming and the end of the streaming, and thus should be only used in
those code paths.

However, as the userspace (libcamera) does not support dual purpose
video nodes, for the time being let's keep the second video node as
V4L2_CAP_META_CAPTURE only to keep the userspace working.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>