When using the OPAL ICP backend we incorrectly pass Linux CPU numbers
rather than HW CPU numbers to OPAL.

Fixes: d7436188 ("powerpc/xics: Add ICP OPAL backend")
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>