powerpc: fix memory leaks in QE library

Fix two memory leaks in the Freescale QE library: add a missing kfree() in
ucc_fast_init() and ucc_slow_init() if the ioremap() fails, and update
ucc_fast_free() and ucc_slow_free() to call iounmap() if necessary.

Based on a patch from Tony Breeds <tony@bakeyournoodle.com>.

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