The dma_mask assignments seem to be missed during refactoring
of arch/arm/mach-s3c24xx. Add them to avoid DMA allocation
failures. Without this patch sound is broken on s3c24xx
with errors reported like:

s3c24xx-dma s3c2410-dma.0: coherent DMA mask is unset
ALSA pcmC0D0p,0:: cannot preallocate for size 524288
s3c24xx-iis s3c24xx-iis: Failed to get DMA channel capabilities,
falling back to period counting: -6
s3c24xx-dma s3c2410-dma.0: coherent DMA mask is unset
...
ALSA pcmC0D0c,0:: cannot preallocate for size 524288
s3c24xx-iis s3c24xx-iis: Failed to get DMA channel capabilities,
falling back to period counting: -6
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>