drm/i915: Only dump dp_m2_n2 configuration when drrs is used

Otherwise it is just an useless empty line.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Suggested-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479397449-27085-1-git-send-email-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -12751,6 +12751,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
 	if (intel_crtc_has_dp_encoder(pipe_config)) {
 		intel_dump_m_n_config(pipe_config, "dp m_n",
 				pipe_config->lane_count, &pipe_config->dp_m_n);
+		if (pipe_config->has_drrs)
 			intel_dump_m_n_config(pipe_config, "dp m2_n2",
 					      pipe_config->lane_count,
 					      &pipe_config->dp_m2_n2);