parisc: Re-enable GENERIC_CPU_DEVICES for !SMP

In commit 62773112

 ("parisc: Switch from GENERIC_CPU_DEVICES to
GENERIC_ARCH_TOPOLOGY") GENERIC_CPU_DEVICES was unconditionally turned
off, but this triggers a warning in topology_add_dev(). Turning it back
on for the !SMP case avoids this warning.

Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Fixes: 62773112

 ("parisc: Switch from GENERIC_CPU_DEVICES to GENERIC_ARCH_TOPOLOGY")
Signed-off-by: Helge Deller <deller@gmx.de>