Add basic infrastructure to test rte_ring_xxx_elem APIs.
Adjust the existing test cases to test for various ring
element sizes.
Signed-off-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
