On some platforms like DM355, the number of EDMA parameter
slots available for EDMA_SLOT_ANY usage are few. In such cases,
if MMC/SD uses 16 slots for each instance of MMC controller,
then the number of slots available for other modules will be
very few.

By passing the number of EDMA slots to be used in MMC driver
from platform data, EDMA slots available for other purposes
can be controlled.
Signed-off-by: Sudhakar Rajashekhara <sudhakar.raj@ti.com>
Acked-by: Kevin Hilman <khilman@deeprootsystems.com>