mmc: dw_mmc: call the dw_mci_prep_stop_abort() by default

mmc: dw_mmc: call the dw_mci_prep_stop_abort() by default

stop_cmdr should be set to values relevant to stop command.
It migth be assigned to values whatever there is mrq->stop or not.
Then it doesn't need to use dw_mci_prepare_command().
It's enough to use the prep_stop_abort for preparing stop command.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>