v3.1.0 Release

• MISRA C-2012 violations fixed (7.4)
• Fixed missing lock in rpmsg_lite_rx_callback() for QNX env.
• Correction of rpmsg_lite_instance structure members description
• Address -Waddress-of-packed-member warnings in GCC9
• Clang update to v10.0.0, code re-formatted
• Added support for several new multicore platforms