ANDROID: add kernel/sched/android.h

Create a place for the android-specific scheduler addons to live so that
merges can happen easier and we have a better view of the technical debt
that is being drug along with the kernel updates.

Start it off with replacing an empty copy of task_may_not_preempt() to
solve the build problem for some devices where they are relying on this
function to be present in the system.

Fixes: 65c99af98b ("Revert "ANDROID: sched: avoid placing RT threads on cores handling softirqs"")
Cc: Quentin Perret <qperret@google.com>
Cc: Will McVicker <willmcvicker@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I4fd94fab3397b3a197b79b2ae27e9490b54cad59

kernel/sched/android.h

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Android scheduler hooks and modifications
+ *
+ * Put all of the android-specific scheduler hooks and changes
+ * in this .h file to make merges and modifications easier.  It's also
+ * simpler to notice what is, and is not, an upstream change this way over time.
+ */
+
+
+/*
+ * task_may_not_preempt - check whether a task may not be preemptible soon
+ */
+static inline bool task_may_not_preempt(struct task_struct *task, int cpu)
+{
+	return false;
+}

kernel/sched/sched.h

@@ -67,6 +67,7 @@
 #include <linux/task_work.h>
 #include <linux/tsacct_kern.h>
 #include <linux/android_vendor.h>
+#include "android.h"
 
 #include <asm/tlb.h>