ioctl: Use asm-generic/ioctls.h on m32r (enables termiox)
This patch converts m32r 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 adds TIOCGRS485 and TIOCGRS485, which are unused by
any driver available on this architecture.
- The generic version adds support for termiox