spi: atmel: Fix DMA-setup for transfers with more than 8 bits per word

spi: atmel: Fix DMA-setup for transfers with more than 8 bits per word

The DMA-slave configuration depends on the whether <= 8 or > 8 bits
are transferred per word, so we need to call
atmel_spi_dma_slave_config() with the correct value.

Signed-off-by: David Mosberger <davidm@egauge.net>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org