Revert "mmc: tmio: fix reset operation"

Revert "mmc: tmio: fix reset operation"

This reverts commit a87852c6b8827b7fece78ae57d871d56e4348e30. It did fix
the issue, but was building on top of already wrong assumptions. The
driver missed that 'hw_reset' was only for resetting remote HW (card)
and not for the IP core. Since we fixed that in a previous patch, we can
now remove this patch to make it clear that 'reset' is for resetting the
IP core only. Also, cancelling DMA will only be called when actually
needed again. It will also allow for further cleanups and better
readability. Note that in addition to the revert, the call in
'tmio_mmc_execute_tuning' will be converted, too, to maintain the
current behaviour.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Tested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Link: https://lore.kernel.org/r/20200820132538.24758-3-wsa+renesas@sang-engineering.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>