mmc: davinci: modify data types of EDMA related variables
Currently DaVinci EDMA driver supports multiple EDMA channel controller
instances. edma_alloc_channel() api returns a 32 bit value which has the
channel controller number in MSB and the EDMA channel number in LSB. The
variables which store the value returned by edma_alloc_channel() have to
be 32 bit wide now.