sh: Add support Renesas SH7763

Renesas SH7763 has 3 SCIF, MMC, LCDC, Ethernet and other.
This patch supprts CPU register's header file.

Signed-off-by: Nobuhiro Iwamatsu <iwamatsu.nobuhiro@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>