drm/edid: Remove drm_select_eld

The only user was i915, which is now gone.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Acked-by: Dave Airlie <airlied@redhat.com> #irc
Cc: dri-devel@lists.freedesktop.org
Link: http://patchwork.freedesktop.org/patch/msgid/1478609742-13603-9-git-send-email-maarten.lankhorst@linux.intel.com