hap-nodejs itself does not require node-gyp rebuilding. Dependencies which do require it:

mdns curve25519-n2 ed25519

I was able to build all of them on my omega 2+. Here is the link:
https://happyche.wordpress.com/2017/12/05/homebridge-on-lede-openwrt-routers/

One thing I needed to do differently was, pasting dns_sd.h file into /usr/include, and not into /usr/include/avahi-compat-libdns_sd.

I can share compiled libpthread.a file on priv.