kernel: cpu: Handle hotplug failure for state CPUHP_AP_IDLE_DEAD

Once the tear down hotplug handler is run cpu is dead and enters
into CPUHP_AP_IDLE_DEAD state. Any callbacks that fail in the state
machine with state < CPUHP_AP_IDLE must be treated as fatal. As this
could result into timer not being migrated away from dead cpu and run
into issues like work queue lock ups, sched_clock timer wrapping to
zero as sched_clock_pll which is in the hrtimer base of cpu being
hotplugged does not get migrated.

Change-Id: I214c329f5a342d676cc26f57dba453d4a2cbe1a6
Signed-off-by: Channagoud Kadabi <ckadabi@codeaurora.org>
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>