powerpc: Tidy up a bit after removal of PowerPC 601.

The removal of the 601 left some standalone blocks from
former if/else. Drop the { } and re-indent.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/31c4cd093963f22831bf388449056ee045533d3b.1601362098.git.christophe.leroy@csgroup.eu