driver: Clear offlined_cpus mask on disabling Jailhouse

This fixes an inconsistency of the offline_cpus mask after disabling
Jailhouse with non-Linux cells running.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
config: Fix specification of PCI devices for h81i

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