mmc: fixup edma stop when data err occur, cause edma halt

mmc: fixup edma stop when data err occur, cause edma halt
	Fast insert and remove sd card make edma equeue, dequeue
frequently. And with unstable fifo data err, if we stop edma, it
terminate all data will been sent later and flush that desc. However,
MHSC hardware fifo byte counter in fault state  because avaliable data
isn't enough, and remain data been teminated by stop edma. So edma req
signal in fault state event we restart edma. We just let edma sent remain
data, and reset fifo to drop these unused data.

<6>[ 1137.707403] mmc0: new SD card at address 1234
<6>[ 1137.708095] mmcblk0: mmc0:1234 SA02G 1.83 GiB
<3>[ 1141.654157] dwmmc_rockchip 10214000.rksdmmc: data_over interrupt timeout!

Signed-off-by: lintao <lintao@rock-chips.com>