video: tegra: dc: cleanup cursor suspend code

video: tegra: dc: cleanup cursor suspend code

DC_DISP_DISP_WIN_OPTIONS was being read but not updated
with ~CURSOR_ENABLE. Removed redundant code and used
existing function set_cursor_enable() which writes back
to DC_DISP_DISP_WIN_OPTIONS to suspend cursor.

bug 200146453

Change-Id: Ie1f9d73e899aa65e58576d743d720a077ce8d1c8
Signed-off-by: Naveen Kumar S <nkumars@nvidia.com>
Reviewed-on: http://git-master/r/929065
(cherry picked from commit 87f4831a3563bcb4146f0ac83d0fe6d981748317)
Reviewed-on: http://git-master/r/930302
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Winnie Hsu <whsu@nvidia.com>