[ARM] 4326/1: S3C24XX: fix sparse errors in DMA code

Fix the following sparse errors in arch/arm/plat-s3c24xx/dma.c:

dma.c:47:30: warning: symbol 'dma_sel' was not declared. Should it be static?
dma.c:883:6: warning: symbol 's3c2410_dma_waitforstop' was not declared. Should it be static?
dma.c:961:1: warning: symbol 's3c2410_dma_started' was not declared. Should it be static?
dma.c:1283:12: warning: symbol 's3c24xx_dma_sysclass_init' was not declared. Should it be static?
dma.c:1295:12: warning: symbol 's3c24xx_dma_sysdev_register' was not declared. Should it be static?
dma.c:1399:25: warning: symbol 's3c2410_dma_map_channel' was not declared. Should it be static?

The patch makes all the relevant functions static.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>