[PATCH] spi/pxa2xx: change default supported DMA burst size to 1

On Fri, Jun 06, 2014 at 01:45:09AM +0800, Chew Chiau Ee wrote:

From: Chew, Chiau Ee <redacted>

This is to fix the SPI DMA transfer failure for speed less than 1M.
If using current DMA burst size setting (16), the Rx data bytes are
invalid due to each data byte is multiplied according to the burst
size setting.

Let's said supposedly we shall receive the following 18 bytes of data:
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18
Instead, the data bytes received consist of "16 bytes of '01' +
2 bytes of '02'" :
01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 01 02 02

Signed-off-by: Chew, Chiau Ee <redacted>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>

Works for me (and individual chips can tune this by passing custom
dma_burst_size if needed).

Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>