ioctl: Use asm-generic/ioctls.h on mn10300 (enables termiox)

This patch converts mn10300 to use asm-generic/ioctls.h instead of its
own version.

The differences between the arch-specific version and the generic
version are as follows:

- The generic version provides TIOCGRS485 and TIOCSRS485 but they
  are unused by any driver available for this architecture.
- The generic version adds support for termiox

Cc: David Howells <dhowells@redhat.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>