OMAP buffers are mapped to userspace in write-combining mode by default.
Add support for cached mappings.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The library is just a wrapper around ioctls. It doesn't provide much
value, and its API is marked as experimental and should thus not be
expected to be stable. As third party library dependencies are always
painful for distributors and packagers, use the ioctls directly for now.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

The Crtc::get_primary_plane() method returns the first primary plane
that supports the CRTC. While being correct, this could lead to multiple
primary planes being associated with the CRTC, which can confuse
applications. To avoid that, return insead the primary plane already
associated with the CRTC if one exists, otherwise keep the current
behaviour.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

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

Inherit MappedFramebuffer and add map()