drm/tegra: Changes for v3.12-rc1

Only a couple of small patches this time around. These are mostly fixes
for minor bugs that showed up, but there is also some preparatory work
that will come in handy for future patches.

* tag 'drm/for-3.12-rc1' of git://anongit.freedesktop.org/tegra/linux:
  drm/tegra: Parse device tree earlier
  gpu: host1x: Sort drivers by probe order
  gpu: host1x: Check for valid host1x pointer
  gpu: host1x: returning success instead of -ENOMEM
  gpu: host1x: fix an integer overflow check
  drm/tegra: hdmi: Make sure clock is enabled before dumping registers