drm/meson: Fix driver bind when only CVBS is available

While introducing HDMI support, component matching on connectors node
were bypassed since no driver would actually bind on the DT node.
But when only a CVBS connector is present, only a single node is found
in the graph, but ignored and a NULL match table is given to the
component code.

This code permits bypassing the components framework by binding directly
the DRM driver when no components needs to be loaded.

Fixes: a41e82e6 ("drm/meson: Add support for components")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/1496067352-8733-1-git-send-email-narmstrong@baylibre.com