drm/i915: don't leak dp_connector at intel_ddi_init

drm/i915: don't leak dp_connector at intel_ddi_init

Regression introduced by:
    commit b66e3ab39e9fa3a7908821e5e577d783c7c0ea62
    Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
        drm/i915: don't init DP or HDMI when not supported by DDI port

Since the commit above it is possible to have a DDI encoder that has
the HDMI connector but not the DP connector (in case the port doesn't
support DP). In this case, we must properly free the DP connector.

We just leak this once, so it's not a big deal.

Reported by kmemleak.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>