drm/amdgpu: all vram is visible for APU (v2)

missed in gmc9.

v2: squash in build fix (Rex)
Signed-off-by: NChunming Zhou <david1.zhou@amd.com>
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -729,6 +729,12 @@ static int gmc_v9_0_mc_init(struct amdgpu_device *adev)
 	adev->gmc.aper_base = pci_resource_start(adev->pdev, 0);
 	adev->gmc.aper_size = pci_resource_len(adev->pdev, 0);
 
+#ifdef CONFIG_X86_64
+	if (adev->flags & AMD_IS_APU) {
+		adev->gmc.aper_base = gfxhub_v1_0_get_mc_fb_offset(adev);
+		adev->gmc.aper_size = adev->gmc.real_vram_size;
+	}
+#endif
 	/* In case the PCI BAR is larger than the actual amount of vram */
 	adev->gmc.visible_vram_size = adev->gmc.aper_size;
 	if (adev->gmc.visible_vram_size > adev->gmc.real_vram_size)