ucc_uart: add support for Freescale QUICCEngine UART

[Timur Tabi]

Arnd Bergmann wrote:

> You can argue that the QS is really a DMA device, but in that case you
> should convert the driver to use the DMA mapping interfaces correctly,
> which I would consider overkill.

I'm confused.  I'm already calling dma_alloc_coherent() and getting a dma_addr_t 
back.  Why do I need to use mapping functions to convert between virtual and 
physical/bus addresses?

-- 
Timur Tabi
Linux kernel developer at Freescale