This patch disables the oshmem layer if there are no SPMLs that
will build. With the limited set of SPMLs available to support
oshmem, many builds end up installing an oshmem library that we
know will not work. There has been a bit of customer confusion
over oshmem, hopefully this will lead customers in the right
direction.
Signed-off-by: Brian Barrett <bbarrett@amazon.com>
