drm/cirrus: Use virtual encoder and connector types

drm/cirrus: Use virtual encoder and connector types

The cirrus driver only works on emulated Cirrus hardware. Use the
correct types for encoder and connector.

As a side effect, the connector has no longer an EDID property. But
neither cirrus emulation nor driver provide any EDID data, so it
makes sense to not pretend that there could be one.

v2:
- mention removed EDID property in commit description (Dmitry)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241029143928.208349-2-tzimmermann@suse.de