Fix command-line tty-device|config parsing

Allow user to add options on both sides of the provided config argument.

For example:

 $ tio -b 9600 am64-evm -e

Before, tio only allowed adding arguments after the config argument.

Implemented as simple as possible by introducing two stage option parsing.

src/main.c

@@ -42,13 +42,15 @@ int main(int argc, char *argv[])
     /* Add error exit handler */
     atexit(&error_exit);
 
-    /* Parse configuration file */
-    config_file_parse(argc, argv);
-    atexit(&config_exit);
-
-    /* Parse command-line options */
+    /* Parse command-line options (1st pass) */
     options_parse(argc, argv);
 
+    /* Parse configuration file */
+    config_file_parse();
+
+    /* Parse command-line options (2nd pass) */
+    options_parse_final(argc, argv);
+
     /* List available serial devices */
     if (option.list_devices)
     {