mmc: tmio: eliminate unused variable 'mmc' warning

Fix below compile warning:
  CC      drivers/mmc/host/tmio_mmc.o
drivers/mmc/host/tmio_mmc.c: In function 'tmio_mmc_suspend':
drivers/mmc/host/tmio_mmc.c:30: warning: unused variable 'mmc'
drivers/mmc/host/tmio_mmc.c: In function 'tmio_mmc_resume':
drivers/mmc/host/tmio_mmc.c:45: warning: unused variable 'mmc'

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>