powerpc/qspinlock: Fix 32-bit build

Some 32-bit configurations don't pull in the spin_begin/end/relax
definitions. Fix is to restore a lost include.

Reported-by: kernel test robot <[email protected]>
Fixes: 84990b1 ("powerpc/qspinlock: add mcs queueing for contended waiters")
Signed-off-by: Nicholas Piggin <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/oe-kbuild-all/[email protected]
Link: https://lore.kernel.org/r/[email protected]

Author: npiggin

arch/powerpc/lib/qspinlock.c

@@ -3,6 +3,7 @@
 #include <linux/compiler.h>
 #include <linux/export.h>
 #include <linux/percpu.h>
+#include <linux/processor.h>
 #include <linux/smp.h>
 #include <linux/topology.h>
 #include <linux/sched/clock.h>