mmc: s3cmci: Drop unused variables in dbg_dumpregs

mmc: s3cmci: Drop unused variables in dbg_dumpregs

The 'imask' and 'bsize' are not used in dbg_dumpregs:

  drivers/mmc/host/s3cmci.c:149:36: warning: variable 'imask' set but not used [-Wunused-but-set-variable]
  drivers/mmc/host/s3cmci.c:148:63: warning: variable 'bsize' set but not used [-Wunused-but-set-variable]

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200903054333.18331-1-krzk@kernel.org
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>