PCI: rockchip: Remove writes to unused registers

Remove write accesses to registers that are marked "unused" (and
therefore read-only) in the technical reference manual (TRM)
(see RK3399 TRM 17.6.8.1)

Link: https://lore.kernel.org/r/20230418074700.1083505-2-rick.wertenbroek@gmail.com
Tested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Rick Wertenbroek <rick.wertenbroek@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

Author: rwk-git

drivers/pci/controller/pcie-rockchip-ep.c

@@ -61,10 +61,6 @@ static void rockchip_pcie_clear_ep_ob_atu(struct rockchip_pcie *rockchip,
 			    ROCKCHIP_PCIE_AT_OB_REGION_DESC0(region));
 	rockchip_pcie_write(rockchip, 0,
 			    ROCKCHIP_PCIE_AT_OB_REGION_DESC1(region));
-	rockchip_pcie_write(rockchip, 0,
-			    ROCKCHIP_PCIE_AT_OB_REGION_CPU_ADDR0(region));
-	rockchip_pcie_write(rockchip, 0,
-			    ROCKCHIP_PCIE_AT_OB_REGION_CPU_ADDR1(region));
 }
 
 static void rockchip_pcie_prog_ep_ob_atu(struct rockchip_pcie *rockchip, u8 fn,
@@ -114,12 +110,6 @@ static void rockchip_pcie_prog_ep_ob_atu(struct rockchip_pcie *rockchip, u8 fn,
 		     PCIE_CORE_OB_REGION_ADDR0_LO_ADDR);
 		addr1 = upper_32_bits(cpu_addr);
 	}
-
-	/* CPU bus address region */
-	rockchip_pcie_write(rockchip, addr0,
-			    ROCKCHIP_PCIE_AT_OB_REGION_CPU_ADDR0(r));
-	rockchip_pcie_write(rockchip, addr1,
-			    ROCKCHIP_PCIE_AT_OB_REGION_CPU_ADDR1(r));
 }
 
 static int rockchip_pcie_ep_write_header(struct pci_epc *epc, u8 fn, u8 vfn,