mmc: sh_mmcif: Terminate DMA transactions when detecting timeout or error

If a DMA transaction fails, terminate all outstanding DMA transfers and
unmap buffers.

Signed-off-by: Teppei Kamijou <teppei.kamijou.yb@renesas.com>
Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
[g.liakhovetski@gmx.de: forward-port, add dma_unmap_sg() in error cases]
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>