arm: rmobile: Move sh-i2c of the address defined to common header

R-Car SoCs of rmobile have same IP of sh-i2c, and have same address.
This moves sh-i2c of the address defined to rcar-base.h as common header of
R-Car SoCs, and headers of each SoCs.

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