mmc: pxamci: remove dead code from pxamci_remove()

These gpio assignments don't make sense, as they are not used anywhere.
Remove the dead code.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>