mmc: block: make function mmc_cqe_issue_type static

The function mmc_cqe_issue_type is local to the source and does
not need to be in global scope, so make it static.

Cleans up sparse warning:
drivers/mmc/core/queue.c:62:21: warning: symbol 'mmc_cqe_issue_type'
was not declared. Should it be static?

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index d839400..5db3880 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -59,8 +59,8 @@ static inline bool mmc_cqe_can_dcmd(struct mmc_host *host)
 	return host->caps2 & MMC_CAP2_CQE_DCMD;
 }
 
-enum mmc_issue_type mmc_cqe_issue_type(struct mmc_host *host,
-				       struct request *req)
+static enum mmc_issue_type mmc_cqe_issue_type(struct mmc_host *host,
+					      struct request *req)
 {
 	switch (req_op(req)) {
 	case REQ_OP_DRV_IN: