TTY: serial/m32r_sio, disband m32r_sio.h

The only needed information from the header is struct old_serial_port.
Move it to m32r_sio.c, make it const and anonymous. And kill the rest
from the header as it is dead stuff.

Given m32r_sio_suspend_port and m32r_sio_resume_port are local to
m32r_sio.c and unused, kill them from .c too.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>