PCI: artpec6: Stop enabling writes to DBI read-only registers

Previously we enabled writes to the DBI read-only registers so the Class
Code fix in dw_pcie_setup_rc() would work.  But now dw_pcie_setup_rc()
enables write permission itself, so we don't need to do it here.

Stop enabling writes to the DBI read-only registers.

Signed-off-by: Hou Zhiqiang <Zhiqiang.Hou@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Roy Zang <tie-fei.zang@freescale.com>

drivers/pci/dwc/pcie-artpec6.c

@@ -141,12 +141,6 @@ static int artpec6_pcie_establish_link(struct artpec6_pcie *artpec6_pcie)
 	artpec6_pcie_writel(artpec6_pcie, PCIECFG, val);
 	usleep_range(100, 200);
 
-	/*
-	 * Enable writing to config regs. This is required as the Synopsys
-	 * driver changes the class code. That register needs DBI write enable.
-	 */
-	dw_pcie_writel_dbi(pci, MISC_CONTROL_1_OFF, DBI_RO_WR_EN);
-
 	/* setup root complex */
 	dw_pcie_setup_rc(pp);