phy: sophgo: 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 <andriy.shevchenko@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/sophgo/phy-cv1800-usb2.c

@@ -11,7 +11,6 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
-#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/phy/phy.h>
 #include <linux/regmap.h>