mmc: Kconfig: Fix spelling mistake "referrered" -> "referred"

There are two spelling mistakes in the config. Fix them.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Link: https://lore.kernel.org/r/20250724112817.142784-1-colin.i.king@gmail.com


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>