UPSTREAM: arm64: cpu hotplug: ensure we mask out CPU_TASKS_FROZEN in notifiers

(cherry picked from commit e56d82a116176f7af9d642b560abbbd3a2b68013)

We have a couple of CPU hotplug notifiers for resetting the CPU debug
state to a sane value when a CPU comes online.

This patch ensures that we mask out CPU_TASKS_FROZEN so that we don't
miss any online events occuring due to suspend/resume.

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Signed-off-by: Pavel Labath <labath@google.com>
Bug: 27189927
Change-Id: I72549149b9bf1f0d05cb17a1db98f9a342c580c0