drm/amdgpu : enable msix for amdgpu driver

We might used out of the msi resources in some cloud project
which have a lot gpu devices(including PF and VF), msix can
provide enough resources from system level view
Signed-off-by: shaoyunl <shaoyun.liu@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_irq.c

@@ -245,8 +245,9 @@ int amdgpu_irq_init(struct amdgpu_device *adev)
 	adev->irq.msi_enabled = false;
 
 	if (amdgpu_msi_ok(adev)) {
-		int ret = pci_enable_msi(adev->pdev);
-		if (!ret) {
+		int nvec = pci_alloc_irq_vectors(adev->pdev, 1, pci_msix_vec_count(adev->pdev),
+					PCI_IRQ_MSI | PCI_IRQ_MSIX);
+		if (nvec > 0) {
 			adev->irq.msi_enabled = true;
 			dev_dbg(adev->dev, "amdgpu: using MSI.\n");
 		}