iommu/omap: Remove couple of unused exported functions

The exported functions omap_foreach_iommu_device() and
omap_iotlb_cr_to_e() have been deleted, as they are no
longer needed.

The function omap_foreach_iommu_device() is not required
after the consolidation of the OMAP IOMMU debug module,
and the function omap_iotlb_cr_to_e() is not required
after making the debugfs entry 'pagetable' read-only.

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>