README: add details on patch submission
README: add details on patch submission

Signed-off-by: Brendan Le Foll <3e0e8c4069934e8b47d99704927a85c66c0ceb33@intel.com>

tripzero/meta-intel-iot-middleware,andreivasiliu2211/meta-intel-iot-middleware,GuojianZhou/meta-intel-iot-middleware