serial: sh-sci: Convert tremaining ctrl_xxx I/O routines to __raw_xxx.

ctrl_xxx() is an antiquated SH interface, while __raw_xxx is the standard
API that accomplishes the same thing. As such, this converts the
remaining sh-sci straggles over, which enables the driver to be wired up
for ARM SH-Mobile CPUs as well.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>