video: tegra: dc: remove android specific fb code

video: tegra: dc: remove android specific fb code

The hack around the white screen issue doesn't seem to prevent the white
screen. Removing it and replacing it with a small change to ignore
duplicate unblanks.

Change-Id: I6fe415b700d8c6e8dbbf989d39d4b4c7465ea6c9
Signed-off-by: Jon Mayo <jmayo@nvidia.com>
Reviewed-on: http://git-master/r/329741
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Chao Xu <cxu@nvidia.com>
Reviewed-by: Jong Kim <jongk@nvidia.com>