mmc: s3cmci: Use proper printk format for iomem pointer

iomem pointers should be printed with pointer format to hide the
actual value and fix warnings when compile testing for 64-bit
architecture:

  drivers/mmc/host/s3cmci.c:1355:46: warning:
    cast from pointer to integer of different size [-Wpointer-to-int-cast]

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200902204847.2764-2-krzk@kernel.org


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>