[POWERPC] qe-uart: add support for Freescale QUICCEngine UART

Add file ucc_uart.c, a serial device driver for the Freescale QUICCEngine.
Update the Kconfig and Makefile accordingly.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>