getmachine info first, then init tty.

Problem report and fix given by:
Prof: Alejandro T. Bello Ruiz <abello@macareo.pucp.edu.pe>

drivers/tty/tty.c

@@ -177,14 +177,14 @@ PUBLIC void main(void)
   printf("TTY\n");
 #endif
 
-  /* Initialize the TTY driver. */
-  tty_init();
-
   /* Get kernel environment (protected_mode, pc_at and ega are needed). */ 
   if (OK != (s=sys_getmachine(&machine))) {
     panic("TTY","Couldn't obtain kernel environment.", s);
   }
 
+  /* Initialize the TTY driver. */
+  tty_init();
+
   /* Final one-time keyboard initialization. */
   kb_init_once();