drm/amdgpu: Avoid fetching vram vendor information

For GFX 9.4.3 APUs, the current method of fetching vram vendor
information is not reliable. Avoid fetching the information.
Signed-off-by: Lijo Lazar <lijo.lazar@amd.com>
Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1952,7 +1952,8 @@ static void gmc_v9_4_3_init_vram_info(struct amdgpu_device *adev)
 	static const u32 regBIF_BIOS_SCRATCH_4 = 0x50;
 	u32 vram_info;
 
-	if (!amdgpu_sriov_vf(adev)) {
+	/* Only for dGPU, vendor informaton is reliable */
+	if (!amdgpu_sriov_vf(adev) && !(adev->flags & AMD_IS_APU)) {
 		vram_info = RREG32(regBIF_BIOS_SCRATCH_4);
 		adev->gmc.vram_vendor = vram_info & 0xF;
 	}