drm/amdgpu: PCI I/O bar can be disabled

PCI I/O bar can be disabled in VBIOS to save the resource. It is often
disabled in large aperture VBIOS. Don't call it an error.

Signed-off-by: Amber Lin <Amber.Lin@amd.com>
Acked-by: Christian König <christian.koenig@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

@@ -885,7 +885,7 @@ static int amdgpu_atombios_init(struct amdgpu_device *adev)
 		atom_card_info->ioreg_read = cail_ioreg_read;
 		atom_card_info->ioreg_write = cail_ioreg_write;
 	} else {
-		DRM_ERROR("Unable to find PCI I/O BAR; using MMIO for ATOM IIO\n");
+		DRM_INFO("PCI I/O BAR is not found. Using MMIO to access ATOM BIOS\n");
 		atom_card_info->ioreg_read = cail_reg_read;
 		atom_card_info->ioreg_write = cail_reg_write;
 	}
@@ -1694,7 +1694,7 @@ int amdgpu_device_init(struct amdgpu_device *adev,
 		}
 	}
 	if (adev->rio_mem == NULL)
-		DRM_ERROR("Unable to find PCI I/O BAR\n");
+		DRM_INFO("PCI I/O BAR is not found.\n");
 
 	/* early init functions */
 	r = amdgpu_early_init(adev);