Code review comment for ~dirk.zimoch/epics-base:raspberryPi

There seem to be a number of possibilities for Raspbian cross-building, the various answers to the stack-overflow question at https://stackoverflow.com/questions/19162072/how-to-install-the-raspberry-pi-cross-compiler-on-my-linux-host-machine show several options. The Github tool-chain that Dirk is using does seem to be the "official" one. A fairly comprehensive alternative set with more recent versions is available at https://github.com/abhiTronix/raspberry-pi-cross-compilers

There is also a post on Medium at https://medium.com/@au42/the-useful-raspberrypi-cross-compile-guide-ea56054de187 that covers resolving library issues using the official tool-chain, but it's configuring application builds using CMAKE and I haven't looked at it in detail.