Clean-up of s3c24x0 nand driver

Clean-up of s3c24x0 nand driver

This patch re-formats the arm920t s3c24x0 nand driver in preparation for changes
to add support for the Embest SBC2440-II Board.

The changes are as follows:
- re-indent the code using Lindent
- make sure register layouts are defined using a C struct
- replace the upper-case typedef'ed C struct names with lower case
non-typedef'ed ones
- make sure registers are accessed using the proper accessor functions
- run checkpatch.pl and fix any error reports

It assumes the following patch has been applied first:
- [U-Boot][PATCH-ARM] CONFIG_SYS_HZ fix for ARM902T S3C24X0 Boards, 05/09/2009
 - patches 1/4, 2/4 and 3/4 of this series

Tested on an Embest SBC2440-II Board with local u-boot patches as I don't have
any s3c2400 or s3c2410 boards but need this patch applying before I can submit
patches for the SBC2440-II Board. Also, temporarily modified sbc2410x, smdk2400,
smdk2410 and trab configs to use the mtd nand driver (which isn't used by any
board at the moment), ran MAKEALL for all ARM9 targets and no new warnings or
errors were found.

Signed-off-by: Kevin Morfitt <kevin.morfitt@fearnside-systems.co.uk>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>