drm/fb: revert the i915 Actually configure untiled displays from master

This code moved in here in master, so revert it the same way.

This is the same revert as 9fa246256e09 ("Revert "drm/i915/fbdev:
Actually configure untiled displays"") in drm-fixes.

Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/drm_fb_helper.c

···
 {
 	struct drm_device *dev = fb_helper->dev;
 	unsigned int count = min(fb_helper->connector_count, BITS_PER_LONG);
-	unsigned long conn_configured, conn_seq;
+	unsigned long conn_configured, conn_seq, mask;
 	int i, j;
 	bool *save_enabled;
 	bool fallback = true, ret = true;
···
 		drm_modeset_backoff(&ctx);
 
 	memcpy(save_enabled, enabled, count);
-	conn_seq = GENMASK(count - 1, 0);
+	mask = GENMASK(count - 1, 0);
 	conn_configured = 0;
 retry:
+	conn_seq = conn_configured;
 	for (i = 0; i < count; i++) {
 		struct drm_fb_helper_connector *fb_conn;
 		struct drm_connector *connector;
···
 		if (conn_configured & BIT(i))
 			continue;
 
-		/* First pass, only consider tiled connectors */
-		if (conn_seq == GENMASK(count - 1, 0) && !connector->has_tile)
+		if (conn_seq == 0 && !connector->has_tile)
 			continue;
 
 		if (connector->status == connector_status_connected)
···
 		conn_configured |= BIT(i);
 	}
 
-	if (conn_configured != conn_seq) { /* repeat until no more are found */
-		conn_seq = conn_configured;
+	if ((conn_configured & mask) != mask && conn_configured != conn_seq)
 		goto retry;
-	}
 
 	/*
 	 * If the BIOS didn't enable everything it could, fall back to have the