iommu/omap: Consolidate OMAP IOMMU modules

iommu/omap: Consolidate OMAP IOMMU modules

The OMAP IOMMU driver was originally designed as modules, and split
into a core module and a thin arch-specific module through the OMAP
arch-specific struct iommu_functions, to scale for both OMAP1 and
OMAP2+ IOMMU variants. The driver can only be built for OMAP2+
platforms currently, and also can only be built-in after the
adaptation to generic IOMMU API. The OMAP1 variant was never added
and will most probably be never added (the code for the only potential
user, its parent, DSP processor has already been cleaned up). So,
consolidate the OMAP2 specific omap-iommu2 module into the core OMAP
IOMMU driver - this eliminates the arch-specific ops structure and
simplifies the driver into a single module that only implements the
generic IOMMU API's iommu_ops.

The following are the main changes:
- omap-iommu2 module is completely eliminated, with the common
  definitions moved to the internal omap-iommu.h, and the ops
  implementations moved into omap-iommu.c
- OMAP arch-specific struct iommu_functions is also eliminated,
  with the ops implementations directly absorbed into the calling
  functions
- iotlb_alloc_cr() is no longer inlined and defined only when
  PREFETCH_IOTLB is defined
- iotlb_dump_cr() is similarly defined only when CONFIG_OMAP_IOMMU_DEBUG
  is defined
- Elimination of the OMAP IOMMU exported functions to register the
  arch ops, omap_install_iommu_arch() & omap_uninstall_iommu_arch()
- Any stale comments about OMAP1 are also cleaned up

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>