[ARM] S3C: Fix S3C24XX build to not include s3c64xx IIS devices

Commit 52da219e added IIS
platform devices, but these do not build on s3c24xx systems
and the file depends on SND_S3C24XX_SOC, which is selected
for all S3C64XX/S3C24XX systems.

As a quick fix, make the dev-audio.o file depends on
SND_S3C64XX_SOC_I2S instead.
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

arch/arm/plat-s3c/Makefile

@@ -34,7 +34,7 @@ obj-$(CONFIG_S3C_DEV_HSMMC)	+= dev-hsmmc.o
 obj-$(CONFIG_S3C_DEV_HSMMC1)	+= dev-hsmmc1.o
 obj-y				+= dev-i2c0.o
 obj-$(CONFIG_S3C_DEV_I2C1)	+= dev-i2c1.o
-obj-$(CONFIG_SND_S3C24XX_SOC)	+= dev-audio.o
+obj-$(CONFIG_SND_S3C64XX_SOC_I2S)	+= dev-audio.o
 obj-$(CONFIG_S3C_DEV_FB)	+= dev-fb.o
 obj-$(CONFIG_S3C_DEV_USB_HOST)	+= dev-usb.o
 obj-$(CONFIG_S3C_DEV_USB_HSOTG)	+= dev-usb-hsotg.o