https://android.googlesource.com/platform/system/core/+/84421d8475ca8262a914b3875ed110fc6187ee74

Add ioprio values directly.

The ioprio.h header is not a uapi header, so remove it's use and
add the two values that this code needs to use.

Bug: 30072483
Change-Id: I5c8b6f40bd60a43f50ac26792f96d2fa3f6db020

diff -u -r ../libcutils-orig/iosched_policy.c ./iosched_policy.c
--- ../libcutils-orig/iosched_policy.c	2017-06-28 13:45:36.296011839 +0200
+++ ./iosched_policy.c	2017-06-28 13:45:47.307888245 +0200
@@ -24,7 +24,8 @@
 #include <cutils/iosched_policy.h>
 
 #if defined(__ANDROID__)
-#include <linux/ioprio.h>
+#define IOPRIO_WHO_PROCESS (1)
+#define IOPRIO_CLASS_SHIFT (13)
 #include <sys/syscall.h>
 #define __android_unused
 #else