drm/amd/amdgpu: fix PCIe dpm feature issue (v3)

use pcie_bandwidth_available to get real link state
to update pcie table.

v2: fix incorrect initialized return value
v3: expand the fetching method about the link width to all asics.
Signed-off-by: Chengming Gui <Jack.Gui@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_device.c

@@ -3625,6 +3625,7 @@ static void amdgpu_device_get_min_pci_speed_width(struct amdgpu_device *adev,
 	struct pci_dev *pdev = adev->pdev;
 	enum pci_bus_speed cur_speed;
 	enum pcie_link_width cur_width;
+	u32 ret = 1;
 
 	*speed = PCI_SPEED_UNKNOWN;
 	*width = PCIE_LNK_WIDTH_UNKNOWN;
@@ -3632,6 +3633,10 @@ static void amdgpu_device_get_min_pci_speed_width(struct amdgpu_device *adev,
 	while (pdev) {
 		cur_speed = pcie_get_speed_cap(pdev);
 		cur_width = pcie_get_width_cap(pdev);
+		ret = pcie_bandwidth_available(adev->pdev, NULL,
+						       NULL, &cur_width);
+		if (!ret)
+			cur_width = PCIE_LNK_WIDTH_RESRV;
 
 		if (cur_speed != PCI_SPEED_UNKNOWN) {
 			if (*speed == PCI_SPEED_UNKNOWN)