mmc: s3cmci: Cast driver data through long

mmc: s3cmci: Cast driver data through long

Since driver data is a pointer, direct casting to integer causes
warning when compile testing for 64-bit architecture:

  drivers/mmc/host/s3cmci.c:1495:17: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]

The actual driver data can be only 0 or 1, so cast it via long and do
not care about any loss of value.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200902204847.2764-3-krzk@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>