mmc: mediatek: Add MMC_CAP_SDIO_IRQ support

This patch enables support SDIO IRQs. It enables
MMC_CAP_SDIO_IRQ & MMC_CAP2_SDIO_IRQ_NOTHREAD
and implement the ->ack_sdio_irq callback.

Signed-off-by: Jjian Zhou <jjian.zhou@mediatek.com>
Signed-off-by: Chaotian Jing <chaotian.jing@mediatek.com>
Signed-off-by: Yong Mao <yong.mao@mediatek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>