Jan Kiszka authored Feb 25, 2019 and Philippe Gerum committed Apr 03, 2019

When a CPU is unplugged, make sure to drop all per-CPU ipipe timer
devices when removing the CPU. Otherwise, we will corrupt the device
list when re-registering the host timer on CPU onlining.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>