drm/tegra: Changes for v4.14-rc1

This contains a couple of fixes and improvements for host1x, with some
preparatory work for Tegra186 support.

The remainder is cleanup and minor bugfixes for Tegra DRM along with
enhancements to debuggability.

There have also been some enhancements to the kernel interfaces for
host1x job submissions and support for mmap'ing PRIME buffers directly,
all of which get the interfaces very close to ready for serious work.

* tag 'drm/tegra/for-4.14-rc1' of git://anongit.freedesktop.org/tegra/linux: (21 commits)
  drm/tegra: Prevent BOs from being freed during job submission
  drm/tegra: gem: Implement mmap() for PRIME buffers
  drm/tegra: Support render node
  drm/tegra: sor: Trace register accesses
  drm/tegra: dpaux: Trace register accesses
  drm/tegra: dsi: Trace register accesses
  drm/tegra: hdmi: Trace register accesses
  drm/tegra: dc: Trace register accesses
  drm/tegra: sor: Use unsigned int for register offsets
  drm/tegra: hdmi: Use unsigned int for register offsets
  drm/tegra: dsi: Use unsigned int for register offsets
  drm/tegra: dpaux: Use unsigned int for register offsets
  drm/tegra: dc: Use unsigned int for register offsets
  drm/tegra: Fix NULL deref in debugfs/iova
  drm/tegra: switch to drm_*_get(), drm_*_put() helpers
  drm/tegra: Set MODULE_FIRMWARE for the VIC
  drm/tegra: Add CONFIG_OF dependency
  gpu: host1x: Support sub-devices recursively
  gpu: host1x: fix error return code in host1x_probe()
  gpu: host1x: Fix bitshift/mask multipliers
  ...