video: tegra: dc: Fix and refactor FRAME_END_INT

video: tegra: dc: Fix and refactor FRAME_END_INT

- Fix a conflict with other DC interrupt masks
  when the DSI driver waits on FRAME_END_INT
- Move generic FRAME_END_INT mask/unmask and
  wait-for functions to dc.c

Bug 1534724

Change-Id: I40e26ada2f0494782979e32c1a22906361b214b5
Signed-off-by: Daniel Solomon <daniels@nvidia.com>
Reviewed-on: http://git-master/r/451186
(cherry picked from commit 24a39c49f63eea704003ee27296f1f70d46bcbd0)
Reviewed-on: http://git-master/r/496580
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Jong Kim <jongk@nvidia.com>
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Tested-by: Bibek Basu <bbasu@nvidia.com>
Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>