thermal/x86_pkg_temp: Make pkg_temp_lock a raw_spinlock_t

The pkg_temp_lock spinlock is acquired in the thermal vector handler which
is truly atomic context even on PREEMPT_RT kernels.

The critical sections are tiny, so change it to a raw spinlock.

Signed-off-by: Clark Williams <williams@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20191008110021.2j44ayunal7fkb7i@linutronix.de