ARC: unbork !LLSC build

[ Upstream commit daaf40e5 ]

Fixes: f7d11e93 locking,arch,arc: Fold atomic_ops
Cc: <stable@kernel.vger.org> # 3.18
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>