drm/i915/audio: set ELD Conn_Type at one place

Keep the driver modifications to ELD together. This also sets the
Conn_Type for G4X DP which wasn't done before.

Clean up the debugs while at it; this is all obvious from the connector
name.

v3: add missing ~ (Rodrigo)

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>