Introduce __smp_{store_release,load_acquire}, and rely on the generic
definitions for smp_{store_release,load_acquire}. This avoids the use
of full ("rw,rw") fences on SMP.
Signed-off-by: NAndrea Parri <parri.andrea@gmail.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>