MX28: Fix MXS MMC DMA issues

The DMA didn't work properly because the DMA descriptor wasn't
properly cleaned after it was used once. Also, the DMA_ENABLE bit
was enabled/disabled too late.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <festevam@freescale.com>
Cc: Andy Fleming <afleming@freescale.com>
1 file changed