mmc: sdhci-pltfm: enable interrupt mode to detect card for ls1021a

Enable interrupt mode to detect card instead of polling mode for
ls1021a by removing the quirk SDHCI_QUIRK_BROKEN_CARD_DETECTION.
This could improve data transferring performance and avoid the call
trace caused by polling card status sometime.

Signed-off-by: Yangbo Lu <yangbo.lu@freescale.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>