spi: atmel: remove unnecessary include

Since commit d5fab59c ("spi: atmel: trivial: remove unused fields in
DMA structure"), the driver is not using any definitions from
linux/platform_data/dma-atmel.h, stop including it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20200930145353.3043699-1-alexandre.belloni@bootlin.com


Signed-off-by: Mark Brown <broonie@kernel.org>