Reimplement the terminal user access via separate syscalls

kernel/dev/dev.c

@@ -3,7 +3,6 @@
 #include "spinlock/spinlock.h"
 #include "std/string.h"
 #include "dev/dev.h"
-#include "dev/termdev.h"
 #include "dev/ps2kbdev.h"
 #include "dev/serialdev.h"
 #include "dev/fbdev.h"
@@ -15,7 +14,6 @@ void dev_init(void) {
   memset(&DEVTABLE, 0, sizeof(DEVTABLE));
   spinlock_init(&DEVTABLE.spinlock);
 
-  termdev_init();
   ps2kbdev_init();
   serialdev_init();
   fbdev_init();