iommu/msm: fix the include guard in iommu.h

msm_soc_version_supports_iommu_v1() was defined outside the guard.

Change-Id: I47a579cf14c159c4cbe44b855067c0b82da7b552
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Signed-off-by: Alex Wong <waiw@codeaurora.org>