Refactor get_port to use FNV-1a hash for consistency across platforms

[deanlee]

resolve commaai/openpilot#34031 :

the issue is caused by a port mismatch between the Mac and the device:

Attempting to connect to zmq endpoint: tcp://172.16.0.20:60942
Expected port on the device: 63557

It seems the static int get_port(std::string endpoint) function returns different port values on macOS and Linux, likely due to platform differences in how std::hash behaves.

This pr fixes the issue where the get_port function returns different port values on macOS and Linux due to platform-specific behavior of std::hash. The mismatch in port values causes connection failures in ZMQ. The solution replacesstd::hashwith a custom FNV-1a hash function to ensure consistent port values across platforms, and reducing the risk of collisions.

[pbassut]

Confirmed this works!
Thank you @deanlee for such quick turn around on this one