mmc: tmio: core: Add end operation into tmio_mmc_dma_ops

Related drivers like renesas_sdhi_internal_dmac are possible
to lack dma unmaping in error cases (for example response timeout).

Since tmio_mmc_finish_request() will be always called in any case,
to fix the issue, add end operation into struct tmio_mmc_dma_ops and
call the operation in tmio_mmc_finish_request() to call dma_ummap API
by the related drivers correctly.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/1590044466-28372-2-git-send-email-yoshihiro.shimoda.uh@renesas.com
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>