mmc: atmel_sdhci: Enable the quirk SDHCI_QUIRK_WAIT_SEND_CMD

To fix the timeout of sending the write command, enable the quirk
SDHCI_QUIRK_WAIT_SEND_CMD.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>