tty: includecheck fix: drivers/char, vt.c

fix the following 'make includecheck' warning:

  drivers/char/vt.c: linux/device.h is included more than once.

Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>