core/cpu: refactor IPI sending
core/cpu: refactor IPI sending

Pull the IPI sending code into its own function where it is used in
two places.

cpu_wake() already checks in_idle, so its caller does not need to
check pm_enabled.

Signed-off-by: Nicholas Piggin <24829078df5003d9dd1dd871ca2aeb0b1cf95ef4@gmail.com>
Signed-off-by: Cédric Le Goater <2d8cace2254d4e43578d21933db015d84bcc468a@kaod.org>

qemu/skiboot,legoater/skiboot,shenki/skiboot,shenki/skiboot,shenki/skiboot,open-power/skiboot,legoater/skiboot,open-power/skiboot,shenki/skiboot,shenki/skiboot,qemu/skiboot,qemu/skiboot,legoater/skiboot,qemu/skiboot,legoater/skiboot,open-power/skiboot,qemu/skiboot,open-power/skiboot,legoater/skiboot,open-power/skiboot