configs: Add more CONFIG_ARMV7_PSCI_NR_CPUS entries

The code had assumed 4 CPUS before and now we have this configurable.
For now, set this to the previous default.

Cc: Chander Kashyap <k.chander@samsung.com>
Cc: Steve Rae <steve.rae@raedomain.com>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>