mmc: sdhci: Fix unexpected data interrupt handling

In the busy response case (i.e. !host->data), an unexpected data interrupt
would result in clearing the data command as though it had completed but
without informing the upper layers and thus resulting in a hang.  Fix by
only clearing the data command for data interrupts that are expected.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org # v4.8+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>