bus/fsl-mc: set coherent dma mask for devices on fsl-mc bus

of_dma_configure() API expects coherent_dma_mask to be correctly
set in the devices. This patch does the needful.

Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>