PCI: qcom-ep: Use the generic dw_pcie_ep_linkdown() API to handle Link Down event

Now that the generic dw_pcie_ep_linkdown() API is available, use it. This
also handles the reinitialization of DWC non-sticky registers in addition
to sending the notification to EPF drivers.

Link: https://lore.kernel.org/linux-pci/20240430-pci-epf-rework-v4-9-22832d0d456f@linaro.org
Tested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Niklas Cassel <cassel@kernel.org>

Author: Mani-Sadhasivam

drivers/pci/controller/dwc/pcie-qcom-ep.c

@@ -641,7 +641,7 @@ static irqreturn_t qcom_pcie_ep_global_irq_thread(int irq, void *data)
 	if (FIELD_GET(PARF_INT_ALL_LINK_DOWN, status)) {
 		dev_dbg(dev, "Received Linkdown event\n");
 		pcie_ep->link_status = QCOM_PCIE_EP_LINK_DOWN;
-		pci_epc_linkdown(pci->ep.epc);
+		dw_pcie_ep_linkdown(&pci->ep);
 	} else if (FIELD_GET(PARF_INT_ALL_BME, status)) {
 		dev_dbg(dev, "Received Bus Master Enable event\n");
 		pcie_ep->link_status = QCOM_PCIE_EP_LINK_ENABLED;