mmc: atmel-mci: fix timeout errors in SDIO mode when using DMA

commit 66b512eda74d59b17eac04c4da1b38d82059e6c9 upstream.

With some SDIO devices, timeout errors can happen when reading data.
To solve this issue, the DMA transfer has to be activated before sending
the command to the device. This order is incorrect in PDC mode. So we
have to take care if we are using DMA or PDC to know when to send the
MMC command.

Change-Id: I4e59286f94f297e6755c794b9bd65bca7a24666a
Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>