[ARM] S3C: Fix ADC driver sparse warning

The symbol 's3c_adc_try' in arch/arm/plat-s3c24xx/adc.c
does not need to be exported and thus should be static.

This fixes the following sparse warning:

adc.c:103:6: warning: symbol 's3c_adc_try' was not declared. Should it be static?
Signed-off-by: NBen Dooks <ben@simtec.co.uk>
Signed-off-by: NBen Dooks <ben-linux@fluff.org>

arch/arm/plat-s3c24xx/adc.c

@@ -100,7 +100,7 @@ static void s3c_adc_dbgshow(struct adc_device *adc)
 		readl(adc->regs + S3C2410_ADCDLY));
 }
 
-void s3c_adc_try(struct adc_device *adc)
+static void s3c_adc_try(struct adc_device *adc)
 {
 	struct s3c_adc_client *next = adc->ts_pend;