drm/i915: Make intel_get_crtc_new_encoder() less oopsy

drm/i915: Make intel_get_crtc_new_encoder() less oopsy

The point of the WARN was to print something, not oops
straight up. Currently that is precisely what happens
if we can't find the connector for the crtc in the atomic
state. Get the dev pointer from the atomic state instead
of the potentially NULL encoder to avoid that.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230413200602.6037-2-ville.syrjala@linux.intel.com
Fixes: 3a47ae201e07 ("drm/i915/display: Make WARN* drm specific where encoder ptr is available")
Reviewed-by: Jani Nikula <jani.nikula@intel.com>