cpm_uart: Pass actual dev ptr to dma_* in ucc and cpm_uart serial

We're currently passing NULL, and really shouldn't be.

Signed-off-by: Becky Bruce <becky.bruce@freescale.com>
Acked-By: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>