system: Add support for getting/setting i/o priorities and include a userspace tool

Signed-off-by: San Mehat <san@google.com>
diff --git a/libcutils/Android.mk b/libcutils/Android.mk
index 93933e2..4c45cc9 100644
--- a/libcutils/Android.mk
+++ b/libcutils/Android.mk
@@ -38,7 +38,8 @@
 	process_name.c \
 	properties.c \
 	threads.c \
-	sched_policy.c
+	sched_policy.c \
+	iosched_policy.c
 
 commonHostSources := \
         ashmem-host.c