staging: media: ipu3: Remove some excess struct member documentation

staging: media: ipu3: Remove some excess struct member documentation

Remove kerneldoc entries for struct members that do not exist, fixing these
warnings:

  ./drivers/staging/media/ipu3/include/uapi/intel-ipu3.h:2522: warning: Excess struct member 'reserved1' description in 'ipu3_uapi_acc_param'
  ./drivers/staging/media/ipu3/include/uapi/intel-ipu3.h:2522: warning: Excess struct member 'reserved2' description in 'ipu3_uapi_acc_param'
  ./drivers/staging/media/ipu3/include/uapi/intel-ipu3.h:2778: warning: Excess struct member '__acc_osys' description in 'ipu3_uapi_flags'

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>