powerpc/qe: Convert qe_ic_lock to raw_spinlock

Interrupt controllers' hooks are executed in the atomic context, so
they are not permitted to sleep (with RT kernels non-raw spinlocks are
sleepable). So, qe_ic_lock has to be a real (non-sleepable) spinlock.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>