[PATCH 13/22] powerpc: Consolidate atomic-machine.h

[Wilco Dijkstra]

Hi Adhemerval,
 
> The __HAVE_64B_ATOMICS can be define based on __WORDSIZE, and
> the __ARCH_ACQ_INSTR, MUTEX_HINT_*, and barriers definition are
> defined by the target cpu.

LGTM.

Reviewed-by: Wilco Dijkstra  <Wilco.Dijkstra@arm.com>

Cheers,
Wilco