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 <[e-mail]>
Signed-off-by: Krzysztof Kozlowski <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Ulf Hansson <[e-mail]>

drivers/mmc/host/sdhci-sprd.c

···
 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,