mmc: mtk-sd: fix two spelling mistakes in comment

spelling mistake fix : "alreay" -> "already"
		       "checksume" -> "checksum"

Signed-off-by: Yu Zhe <yuzhe@nfschina.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20221110072819.11530-1-yuzhe@nfschina.com


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