s390/nohz: use a per-cpu flag for arch_needs_cpu

Move the nohz_delay bit from the s390_idle data structure to the
per-cpu flags. Clear the nohz delay flag in __cpu_disable and
remove the cpu hotplug notifier that used to do this.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --cc arch/s390/include/asm/cputime.h
Simple merge

diff --cc arch/s390/include/asm/processor.h
Simple merge

diff --cc arch/s390/kernel/irq.c
Simple merge

diff --cc arch/s390/kernel/smp.c
Simple merge

diff --cc arch/s390/kernel/vtime.c
Simple merge

diff --cc drivers/s390/cio/airq.c
Simple merge

diff --cc drivers/s390/cio/cio.c
Simple merge

diff --cc include/linux/tick.h
Simple merge

diff --cc kernel/time/tick-sched.c
Simple merge