thermal/x86_pkg_temp: Move work into package struct

Delayed work structs are held in a static percpu storage, which makes no
sense at all because work is strictly per package and we never schedule
more than one work per package.

Aside of that the work cancelation in the hotplug is broken when the work
is queued on the outgoing cpu and canceled. Nothing reschedules the work on
another online cpu in the package, so the interrupts stay disabled and the
work_scheduled flag stays active.

Move the delayed work struct into the package struct, which is the only
sensible place to have it.

To simplify the cancelation logic schedule the work always on the cpu which
is the target for the sysfs files. This is required so the cancelation
logic in the cpu offline path cancels only when the outgoing cpu is the
current target and reschedule the work when there is still a online
CPU in the package.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>