mmc: mediatek: fix SDIO irq issue

mmc: mediatek: fix SDIO irq issue

SDIO irq is not triggered by low level, but by falling edge in our
previous IC. This mechanism only have one chance to catch the SDIO irq
if a SDIO irq comes within the multiple block transmission. This SDIO
irq may be easily lost, because falling edge appears only once within 2
clock after data transmission is completed.

SDIO irq recheck mechanism will make sure all irqs can be
processed correctly.

Signed-off-by: Yong Mao <yong.mao@mediatek.com>
Link: https://lore.kernel.org/r/1585299097-6897-2-git-send-email-yong.mao@mediatek.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>