mmc: sdhci: Add CQE support

Add an interrupt hook and helper functions for enabling, disabling and
delivering interrupts to a CQE.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Tested-by: Ludovic Desroches <ludovic.desroches@microchip.com>