add Mac timestamp support

[RootLUG]

As title says, add a support for logging Mac timestamp (e.g. the value in microseconds of the MAC's 64-bit 802.11 Time Synchronization Function timer when the first bit of the MPDU arrived at the MAC). This must be provided by the driver other the field is missing/empty in the radiotap header when capturing traffic. https://www.radiotap.org/fields/TSFT.html

This would increase the capabilities as the "timestamp" of packet in pcap is not of a high accuracy and depends on load/processing speed as compared to the mac timestamp which would allow the devices to be used in more specialized cases such as multilateration of radio signal by computing time-of-flight (for which mac timestamp is needed to get high enough precision)

[morrownr]

@RootLUG

I can appreciate your suggestion but I am not going to be adding features to this driver. I hope to have time to be part of an effort later this year to bring a standards compliant driver for this chipset to the Linux kernel. I will post here if it comes to pass.

[RootLUG]

Understood, great that there is a plan to make it officially supported in a linux kernel. Thank you for your hard work and contributions