iommu/omap: Remove bogus version check in context save/restore

The omap2_iommu_save_ctx() and omap2_iommu_restore_ctx()
performs a sanity version check against a fixed value
that is correct only for OMAP2/OMAP3 IOMMUs. This fixed check
does not scale for all OMAP2+ IOMMUs and is not absolutely
required, so it has been removed.

Signed-off-by: Suman Anna <s-anna@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>