PCI: dwc-plat: Drop dw_plat_pcie_of_match[] forward declaration

The dw_plat_pcie_of_match[] forward declaration was required when
dw_plat_pcie_probe() called of_match_device().  5c204204cf ("PCI:
designware-plat: Prefer of_device_get_match_data()") replaced that with
of_device_get_match_data(), which no longer needs the declaration.

Drop the unnecessary forward declaration.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20220624143428.8334-19-Sergey.Semin@baikalelectronics.ru
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>

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

@@ -29,8 +29,6 @@ struct dw_plat_pcie_of_data {
 	enum dw_pcie_device_mode	mode;
 };
 
-static const struct of_device_id dw_plat_pcie_of_match[];
-
 static const struct dw_pcie_host_ops dw_plat_pcie_host_ops = {
 };