This commit adds implementations of opal_atomic_ll_32/64 and
opal_atomic_sc_32/64. These atomics can be used to implement more
efficient lifo/fifo operations on supported platforms. The only
supported platform with this commit is powerpc/power.
This commit also adds an implementation of opal_atomic_swap_32/64 for
powerpc.
Tested with Power8.
Signed-off-by: Nathan Hjelm <hjelmn@lanl.gov>