ARM: S3C2412: move mach-s3c2412/* into mach-s3c24xx/

This patch moves S3C2412 stuff into mach-s3c24xx/ directory
so that we can merge the s3c24 series' directories to the
just one mach-s3c24xx/ directory.

And this patch is including following.
- re-ordered alphabetically by option text at Kconfig and Makefile

Cc: Ben Dooks <ben-linux@fluff.org>
[heiko@sntech.de: move 'config S3C2412_PM_SLEEP' to use it for S3C2416]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>