PXA2x0 DMAC alignment check

[KIYOHARA Takashi]

Hi! all,

My pxa255 machine happens error when start write DMA to MMC.
Error message is

pxamci0: couldn't start dma xfer. (error=14)

This reason is fault alignment on pxadmac. It checks alignment
to 8bytes boundary always. But PXA255/270 datasheets describing
4byte allowed, if internal peripherals.

However pxa2x0 DMAC has more constraints for alignment.
We need more check?

This patch tested only on NETBOOK PRO(hpcarm. coming soon:).

Thanks,
--
kiyohara