PCI: designware-plat: Remove unused platform data

The designware-plat driver never uses the platform drvdata pointer, so
don't bother setting it.  No functional change intended.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/host/pcie-designware-plat.c

@@ -108,7 +108,6 @@ static int dw_plat_pcie_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
-	platform_set_drvdata(pdev, dw_plat_pcie);
 	return 0;
 }