drm/i915: fix DP get_hw_state return value

If we couldn't find a pipe we shouldn't return true.  This might be even
better as a WARN though, since it should be impossible to have the port
enabled without a pipe selected.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_dp.c

@@ -1361,7 +1361,7 @@ static bool intel_dp_get_hw_state(struct intel_encoder *encoder,
 			      intel_dp->output_reg);
 	}
 
-	return true;
+	return false;
 }
 
 static void intel_disable_dp(struct intel_encoder *encoder)