powerpc: implement barrier primitives

Instead of referring to the Linux header including the barrier
macros, copy over the rather simple implementation for the PowerPC
barrier instructions kvmtool uses. This fixes build for powerpc.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
1 file changed