doc: force include interface header files first

Force include interface header files first before other files
under include. This is due to doxygen always using the first
found item during linking. Because of this, without forcing
the interface definitions first, almost all of these would
link to the same named items, for example, under ARC header
files instead. Hence the need to manually shuffle the items
so linking would actually link to the correct items.

Note that this only works with functions and macros that are
actually defined in the interface file. A simple doc section
with @def would not work as this is not an actual definition.

Signed-off-by: Daniel Leung <daniel.leung@intel.com>