mmc: sdhci-sprd: Remove unused of_gpio.h

of_gpio.h is deprecated and subject to remove.
The driver doesn't use it, simply remove the unused header.

Signed-off-by: Andy Shevchenko <[e-mail]>
Reviewed-by: Baolin Wang <[e-mail]>
Acked-by: Adrian Hunter <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Ulf Hansson <[e-mail]>

drivers/mmc/host/sdhci-sprd.c

···
 #include <linux/mmc/mmc.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>