Newer ptp support

[datdenkikniet]

TODO:

• [x] Support for stm32f4xx
• [x] Support for stm32f107
• [x] Properly document how to use PacketId to obtain information
• [x] Write example(s)
• [x] Verify whether ETH_PTPTSSR exists on stm32f107 Edit: it does not

Add support for PTP timestamping of RX and TX packets

Legwork courtesy of @korken89 :)