unified: Tweak pipe API parameters

 - Reorders parameters where necessary
 - Adds alignment parameter to K_PIPE_DEFINE()
 - Renames parameters where necessary so they are sync'd
   between header and source files

Change-Id: I4f2367abc28aff646cc90beb9f08bb266e143b0c
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>
5 files changed