Do not create coreboot table if using OpROM instead of GOP FB

Author: mintsuki

src/coreboot.c

@@ -33,6 +33,10 @@ CbCheckSum16 (
 
 int build_coreboot_table(struct csmwrap_priv *priv)
 {
+    if (priv->video_type == CSMWRAP_VIDEO_OPROM) {
+        return 0;
+    }
+
         void *p = (void *)CB_TABLE_START;
         void *tables;
         uint32_t table_entries = 0;