drm/amdgpu: skip BAR resizing if the bios already did it

[ Upstream commit b7221f2b ]

No need to do it again.

Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Stable-dep-of: 099bffc7 ("drm/amdgpu: disable BAR resize on Dell G5 SE")
Signed-off-by: Sasha Levin <sashal@kernel.org>