mfd: core: Copy DMA mask and params from parent

The child device intends to perform DMA operations then it needs a dma
mask and params set. This patches copies them from the parent device.

Signed-off-by: Benedikt Spranger <b.spranger@linutronix.de>
Signed-off-by: Holger Dengler <dengler@linutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>