mmc: sdhci-sprd: use sdhci_sprd_writew

The sdhci_sprd_writew() was defined by never used in sdhci_ops:

    drivers/mmc/host/sdhci-sprd.c:134:20: warning: unused function 'sdhci_sprd_writew'

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20210601095403.236007-2-krzysztof.kozlowski@canonical.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-sprd.c

@@ -393,6 +393,7 @@ static void sdhci_sprd_request_done(struct sdhci_host *host,
 static struct sdhci_ops sdhci_sprd_ops = {
 	.read_l = sdhci_sprd_readl,
 	.write_l = sdhci_sprd_writel,
+	.write_w = sdhci_sprd_writew,
 	.write_b = sdhci_sprd_writeb,
 	.set_clock = sdhci_sprd_set_clock,
 	.get_max_clock = sdhci_sprd_get_max_clock,