PCI: dwc: pci-dra7xx: Fix compilation when !CONFIG_GPIOLIB

PCI: dwc: pci-dra7xx: Fix compilation when !CONFIG_GPIOLIB

If CONFIG_GPIOLIB is not selected the compilation results in the
following build errors:

drivers/pci/controller/dwc/pci-dra7xx.c:
 In function dra7xx_pcie_probe:
drivers/pci/controller/dwc/pci-dra7xx.c:777:10:
 error: implicit declaration of function devm_gpiod_get_optional;
 did you mean devm_regulator_get_optional? [-Werror=implicit-function-declaration]

  reset = devm_gpiod_get_optional(dev, NULL, GPIOD_OUT_HIGH);

drivers/pci/controller/dwc/pci-dra7xx.c:778:45: error: ‘GPIOD_OUT_HIGH’
undeclared (first use in this function); did you mean ‘GPIOF_INIT_HIGH’?
  reset = devm_gpiod_get_optional(dev, NULL, GPIOD_OUT_HIGH);
                                             ^~~~~~~~~~~~~~
                                             GPIOF_INIT_HIGH

Fix them by including the appropriate header file.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
[lorenzo.pieralisi@arm.com: commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>