drm/vc4: txp: Initialise the CRTC before the encoder and connector

It makes more sense to register the CRTC before the encoder and
connectors, so let's move our call around.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20221123-rpi-kunit-tests-v1-16-051a0bb60a16@cerno.tech