tile: Add support for handling PMC hardware

The PMC module is used by perf_events, oprofile and watchdogs.

Signed-off-by: Zhigang Lu <zlu@tilera.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index b3692ce..3067b15 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -66,6 +66,10 @@
 config GENERIC_TIME_VSYSCALL
 	def_bool y
 
+# Enable PMC if PERF_EVENTS, OPROFILE, or WATCHPOINTS are enabled.
+config USE_PMC
+	bool
+
 # FIXME: tilegx can implement a more efficient rwsem.
 config RWSEM_GENERIC_SPINLOCK
 	def_bool y