[oe] meta-linaro README info on sending patches

[Khem Raj]

Marcin,Riku

The linaro OE layers need updating the README files reflecting some of the essential fields. Maintainers and where the upstream patches
are sent to and any other relevant information thats needed in patches for linaro layers, current README is at top of meta-linaro which is fine
however the meta-aarch64 and meta-linaro-toolchain also need there READMEs detailing on how to use these layers in conjunction with OE
universe. See the READMEs of some of layers under meta-openembedded umbrella for guidelines and http://openembedded.org/wiki/Layers_FAQ
especially where it describes the need for README and its contents

Thanks
-Khem