drm/tegra: Changes for v3.19-rc1

The highlights in this pull request are:

  * IOMMU support: The Tegra DRM driver can now deal with discontiguous
    buffers if an IOMMU exists in the system. That means it can allocate
    using drm_gem_get_pages() and will map them into IOVA space via the
    IOMMU API. Similarly, non-contiguous PRIME buffers can be imported
    from a different driver, which allows better integration with gk20a
    (nouveau) and less hacks.

  * Universal planes: This is precursory work for atomic modesetting and
    will allow hardware cursor support to be implemented on pre-Tegra114
    where RGB cursors were not supported.

  * DSI ganged-mode support: The DSI controller can now gang up with a
    second DSI controller to drive high resolution DSI panels.

Besides those bigger changes there is a slew of fixes, cleanups, plugged
memory leaks and so on.

* tag 'drm/tegra/for-3.19-rc1' of git://people.freedesktop.org/~tagr/linux: (44 commits)
  drm/tegra: gem: Check before freeing CMA memory
  drm/tegra: fb: Add error codes to error messages
  drm/tegra: fb: Properly release GEM objects on failure
  drm/tegra: Detach panel when a connector is removed
  drm/tegra: Plug memory leak
  drm/tegra: gem: Use more consistent data types
  drm/tegra: fb: Do not destroy framebuffer
  drm/tegra: gem: dumb: pitch and size are outputs
  drm/tegra: Enable the hotplug interrupt only when necessary
  drm/tegra: dc: Universal plane support
  drm/tegra: dc: Registers are 32 bits wide
  drm/tegra: dc: Factor out DC, window and cursor commit
  drm/tegra: Add IOMMU support
  drm/tegra: Fix error handling cleanup
  drm/tegra: gem: Use dma_mmap_writecombine()
  drm/tegra: gem: Remove redundant drm_gem_free_mmap_offset()
  drm/tegra: gem: Cleanup tegra_bo_create_with_handle()
  drm/tegra: gem: Extract tegra_bo_alloc_object()
  drm/tegra: dsi: Set up PHY_TIMING & BTA_TIMING registers earlier
  drm/tegra: dsi: Replace 1000000 by USEC_PER_SEC
  ...