[PATCHv2] mmc: dw_mmc: change to use recommended reset procedure

Sonny Rao wrote:

This patch changes the fifo reset code to follow the reset procedure
outlined in the documentation of Synopsys  Mobile storage host databook
7.2.13.

v2: Add Generic DMA support
    per the documentation, move interrupt clear before wait
    make the test for DMA host->use_dma rather than host->using_dma
    add proper return values (although it appears no caller checks)

Above changes should be put after following '---'.

Signed-off-by: Sonny Rao <redacted>
Signed-off-by: Yuvaraj Kumar C D <redacted>
---

Here.

- Kukjin

 drivers/mmc/host/dw_mmc.c | 55
++++++++++++++++++++++++++++++++++++++++++++++-
 drivers/mmc/host/dw_mmc.h |  1 +
 2 files changed, 55 insertions(+), 1 deletion(-)