powerpc/eeh: Add missing #ifdef CONFIG_IOMMU_API
powerpc/eeh: Add missing #ifdef CONFIG_IOMMU_API

Some new functions are exposed for use by the IOMMU code but
won't build when CONFIG_IOMMU_API isn't set, so shield them
appropriately.

Signed-off-by: Benjamin Herrenschmidt <a7089bb6e7e92505d88aaff006cbdd60cc9120b6@kernel.crashing.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs