drm/amdgpu: Notify sbios device ready before send request

it is required if a platform supports PCIe root complex
core voltage reduction. After receiving this notification,
SBIOS can apply default PCIe root complex power policy.

Reviewed-by: Alex Deucher <[e-mail]>
Signed-off-by: Rex Zhu <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>
Cc: [e-mail]

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

···
 	size_t size;
 	u32 retry = 3;
 
+	if (amdgpu_acpi_pcie_notify_device_ready(adev))
+		return -EINVAL;
+
 	/* Get the device handle */
 	handle = ACPI_HANDLE(&adev->pdev->dev);
 	if (!handle)