mmc: sdhci: add define for suspend/resume capability

This patch adds the missing define for the suspend/resume
capability (according to SD Host Controller spec).

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Acked-by: Scott Branden <scott.branden@broadcom.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>