drm/amdgpu: check for LINEAR_ALIGNED correctly in check_tiling_flags_gfx6

[ Upstream commit 11317d29 ]

Fix incorrect check.

Signed-off-by: Marek Olšák <marek.olsak@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>