Introduce mem_desc, which holds all information needed for a buffer.
Implement helper functions for allocation and freeing that use this
data type.
Change-Id: I82c88595d058d4fb8c5c5fbf19d13269e48e422f
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/712699