mmc: config help typo fix

Fix typo in description of MMC_QUIRKS config option.

Signed-off-by: Joel Johnson <mrjoel@lixil.net>
diff --git a/drivers/mmc/Kconfig b/drivers/mmc/Kconfig
index 6371ffe..2f0eedc 100644
--- a/drivers/mmc/Kconfig
+++ b/drivers/mmc/Kconfig
@@ -79,7 +79,7 @@
 	help
 	  Some cards and hosts may sometimes behave unexpectedly (quirks).
 	  This option enable workarounds to handle those quirks. Some of them
-	  are enabled by default, other may require additionnal flags or are
+	  are enabled by default, other may require additional flags or are
 	  enabled by the host driver.
 
 config MMC_HW_PARTITIONING