arm: s3c: Unify the S3C24xx SDI structure

Unify the register structure so they can be easily used across all
of S3C24xx lineup.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Cc: Pantelis Antoniou <panto@antoniou-consulting.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>