ARM: ux500: Pass MSP DMA platform data though AUXDATA

It isn't currently possible to pass all platform specific configuration
though Device Tree. Thinks like device names used in the clock
infrastructure, call-backs and DMA information have to be passed in via
AUXDATA structures and the MSP is no exception. Here we're passing DMA
settings.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>