powerpc/xive: Remove now useless pr_debug statements

Those overly verbose statement in the setup of the pool VP
aren't particularly useful (esp. considering we don't actually
use the pool, we configure it bcs HW requires it only). So
remove them which improves the code readability.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>