drivers: renesas: io: Move to common

Move io driver code to common directory, so that the same
code can be re-used by both R-Car Gen3 and RZ/G2 platforms.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Change-Id: Ic661e415c91a1fbfd5eee3bba86466037e51574b
10 files changed