mmc: Improve function name when aborting a tuning cmd

mmc: Improve function name when aborting a tuning cmd

'mmc_abort_tuning()' made me think tuning gets completely aborted.
However, it sends only a STOP cmd to cancel the current tuning cmd.
Tuning process may still continue after that. So, rename the function to
'mmc_send_abort_tuning()' to better reflect all this.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20210608180620.40059-1-wsa+renesas@sang-engineering.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>