drm/amdgpu: Don't do FB resize under A+A config

Disable PCIe BAR resizing on A+A config. It's not needed because we won't use the
PCIe BAR, but it breaks the PCI BAR configuration with the current SBIOS.

Error message of FB BAR resize failure under A+A:

[  154.913731] [drm:amdgpu_device_resize_fb_bar [amdgpu]] *ERROR* Problem resizing BAR0 (-22).
Signed-off-by: Oak Zeng <Oak.Zeng@amd.com>
Reviewed-by: Amber Lin <Amber.Lin@amd.com>
Reviewed-by: Felix Kuehling <Felix.kuehling@amd.com>
Reviewed-by: Christian Koenig <Christian.Koenig@amd.com>
Tested-by: Amber Lin <Amber.Lin@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1249,7 +1249,8 @@ static int gmc_v9_0_mc_init(struct amdgpu_device *adev)
 		adev->nbio.funcs->get_memsize(adev) * 1024ULL * 1024ULL;
 	adev->gmc.real_vram_size = adev->gmc.mc_vram_size;
 
-	if (!(adev->flags & AMD_IS_APU)) {
+	if (!(adev->flags & AMD_IS_APU) &&
+	    !adev->gmc.xgmi.connected_to_cpu) {
 		r = amdgpu_device_resize_fb_bar(adev);
 		if (r)
 			return r;