mmc: android-goldfish: remove incorrect __iomem annotation

Make sparse happy:

drivers/mmc/host/android-goldfish.c:535:56: sparse: incorrect type in
argument 3 (different address spaces)

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>