PCI: dwc: Remove unnecessary header include (of_gpio.h)

Remove unnecessary header include (of_gpio.h) since it doesn't provide
any needed symbols.
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Jingoo Han <jingoohan1@gmail.com>

drivers/pci/controller/dwc/pcie-designware-plat.c

@@ -13,7 +13,6 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/of_device.h>
-#include <linux/of_gpio.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/resource.h>