media: staging/intel-ipu3: remove TODO item about acronyms

The Imgu acronyms are moved from header file into Document by previous
commit b8726aea ("media: ipu3: update meta format documentation"), so
the item can be removed from TODO list now.

[Sakari Ailus: Use commit [0-9a-f]{12} plus subject]

Signed-off-by: Bingbu Cao <bingbu.cao@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/ipu3/TODO

@@ -8,9 +8,6 @@ staging directory.
 - IPU3 driver documentation (Laurent)
   Comments on configuring v4l2 subdevs for CIO2 and ImgU.
 
-- uAPI documentation:
-  Move acronyms to doc-rst file. (Mauro)
-
 - Switch to yavta from v4l2n in driver docs.
 
 - Elaborate the functionality of different selection rectangles in driver