mmc: jz4740: remove unused struct component card_detect_irq

I have not found any user for this struct component.

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/415ea1cb85eedc12f0c2f70da9a1ae3885bdd091.1608714110.git.hns@goldelico.com


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