Create KernelSubmissions.md

Add submission policy

Reference-Platform/KernelSubmissions.md

@@ -0,0 +1,20 @@
+The reference platform kernel is located at:
+
+  https://github.com/Linaro/rpk master
+
+Changes for the reference platform kernel should have been posted upstream for
+the current development kernel prior to submission to the reference platform
+kernel. Changes do not need to have been accepted, they only need to have been
+posted since the last merge window. They *do* need to work with other
+changes in the reference platform kernel and meet quality standards but can
+still be in review, the full policy can be seen in [KernelPolicy.md]
+
+To submit changes:
+
+1. Make a git branch based off Linus' most recent -rc1 tag with the
+   changes
+2. Create a tag (ideally signed using 'git tag -s'). The tag message should
+   describe the change, why it is being proposed for the reference platform
+   and link to the upstream submission (ideally using thread.gmane.org).
+3. Send a pull request for the tag generated using 'git request-pull' to
+  Mark Brown <broonie@linaro.org> and the RPK list (TBD).