iommu/arm-smmu: Fix DOMAIN_ATTR_S1_BYPASS check

change "iommu/arm-smmu: Support DOMAIN_ATTR_S1_BYPASS"
checks the wrong bit when determine whether to bypass or not
to bypass stage1 translation. Fix it.

CRs-Fixed: 995213
Change-Id: Id347f540f866be6b8442d5f166c6cf7b0ae4c000
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>