CONFIG_ARCH_S3C24XX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

Samsung S3C24XX SoCs

modulename: setup-i2c.ko

and/or

irq-s3c24xx.ko

configname: CONFIG_ARCH_S3C24XX

ARM system type
└─>Samsung S3C24XX SoCs
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Samsung S3C2410, S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443
and S3C2450 SoCs based systems, such as the Simtec Electronics BAST
(<http://www.simtec.co.uk/products/EB110ITX/>), the IPAQ 1940 or the
Samsung SMDK2410 development board (and derivatives).

source code:
arch/arm/mach-s3c24xx/setup-i2c.c