ARM: ep93xx: simone: enable DMA on the SPI host

The SPI host on the SIM.ONE is used for the MMC/SD card and
will badly need this turbo boost.

Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>