sh: Add sci_rxd_in of SH4-202

SH4-202 doesn't have SCSXX1. But it is treated so that there is SCSPTR1 in
current code. This patch add sci_rxd_in of SH4-202.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>