powerpc: restore alphabetic order in Kconfig

This patch restores the alphabetic order which was broken by
commit 1e0fc9d1 ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX
for some configs")

Fixes: 1e0fc9d1

 ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>