mmc: mediatek: make function msdc_cqe_disable() static

The sparse tool complains as follows:

drivers/mmc/host/mtk-sd.c:2269:6: warning:
 symbol 'msdc_cqe_disable' was not declared. Should it be static?

This function is not used outside of mtk-sd.c, so this commit
marks it static.

Fixes: 88bd652b ("mmc: mediatek: command queue support")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Acked-by: Chun-Hung Wu <chun-hung.wu@mediatek.com>
Link: https://lore.kernel.org/r/20200727171129.2945-1-weiyongjun1@huawei.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/mtk-sd.c

@@ -2266,7 +2266,7 @@ static void msdc_cqe_enable(struct mmc_host *mmc)
 	msdc_set_timeout(host, 1000000000ULL, 0);
 }
 
-void msdc_cqe_disable(struct mmc_host *mmc, bool recovery)
+static void msdc_cqe_disable(struct mmc_host *mmc, bool recovery)
 {
 	struct msdc_host *host = mmc_priv(mmc);