gpio-amd8111: add release_region on ioport_map failure

Commit ffe4770b

 ("gpio-amd8111: check ioport_map return value")
adds the error check on ioport_map(). It doesnt release the requested region.

On failure this patch release the region that has requested before.

Signed-off-by: Varka Bhadram <varkab@cdac.in>
Reported-by: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>